2,581 research outputs found

    Deep-Water Mining Open Pits

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    Promising Deposits at the Territory of Ukraine

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    Bose-Einstein correlations at LEP and Tevatron energies

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    Using the Bose-Einstein correlations (BEC) implemented in PYTHIA we investigated a possibility of the CDF experiment at the Tevatron to see the two-particle correlations in the final state of interactions. The approach based on quantum field theory at finite temperature was applied to the ALEPH data at LEP, and the BEC important parameters were retrieved.Comment: 5 pages, 4 figures, 1 table. Based on the talk gived at The 6th international workshop on very high multiplicity physics, JINR Dubna, 16-17 april 2005. In Table 1. the sign of error adde

    Modeling the Enceladus plume--plasma interaction

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    We investigate the chemical interaction between Saturn's corotating plasma and Enceladus' volcanic plumes. We evolve plasma as it passes through a prescribed H2O plume using a physical chemistry model adapted for water-group reactions. The flow field is assumed to be that of a plasma around an electrically-conducting obstacle centered on Enceladus and aligned with Saturn's magnetic field, consistent with Cassini magnetometer data. We explore the effects on the physical chemistry due to: (1) a small population of hot electrons; (2) a plasma flow decelerated in response to the pickup of fresh ions; (3) the source rate of neutral H2O. The model confirms that charge exchange dominates the local chemistry and that H3O+ dominates the water-group composition downstream of the Enceladus plumes. We also find that the amount of fresh pickup ions depends heavily on both the neutral source strength and on the presence of a persistent population of hot electrons.Comment: 10 pages, 1 table, 2 figure

    Rigorous results on the local equilibrium kinetics of a protein folding model

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    A local equilibrium approach for the kinetics of a simplified protein folding model, whose equilibrium thermodynamics is exactly solvable, was developed in [M. Zamparo and A. Pelizzola, Phys. Rev. Lett. 97, 068106 (2006)]. Important properties of this approach are (i) the free energy decreases with time, (ii) the exact equilibrium is recovered in the infinite time limit, (iii) the equilibration rate is an upper bound of the exact one and (iv) computational complexity is polynomial in the number of variables. Moreover, (v) this method is equivalent to another approximate approach to the kinetics: the path probability method. In this paper we give detailed rigorous proofs for the above results.Comment: 25 pages, RevTeX 4, to be published in JSTA

    Ureteroscopic lithotripsy for ureteral stones in children using holmium: yag laser energy: results of a multicentric survey

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    BACKGROUND: Holmium:YAG (Ho:YAG) laser lithotripsy has broadened the indications for ureteroscopic stone managements in adults, but few evidence are currently available in the pediatric population. OBJECTIVE: This article aimed to assess the outcome of Ho:YAG laser lithotripsy during retrograde ureteroscopic management of ureteral stones in different locations in children. STUDY DESIGN: The medical records of 149 patients (71 boys and 78 girls; median age 9.2 years) treated with Ho:YAG laser ureteroscopic lithotripsy in five international pediatric urology units over the last 5 years were retrospectively reviewed. Exclusion criteria included patients with renal calculi and/or with a history of ipsilateral stricture, renal failure, active urinary tract infection, or coagulation disorder. RESULTS: Stones were treated with dusting technique in all cases. The median stone size was 10.3 mm (range 5-17). Stones were located in the distal ureter in 77 cases (51.7%), in the middle ureter in 23 cases (15.4%), and in the proximal ureter in 49 cases (32.9%). The median operative time was 29.8 min (range 20-95). Intra-operative complications included five bleedings (3.3%) and seven stone retropulsions (4.7%). Overall stone-free rate was 97.3%. Overall postoperative complications rate was 4.0% and included two cases of stent migration (1.3%) (Clavien II) and four residual stone fragments (2.7%) that were successfully treated using the same technique (Clavien IIIb). On multivariate analysis, re-operation rate was significantly dependent on the proximal stone location and presence of residual fragments >2 mm (P = 0.001). DISCUSSION: This study is one of the largest pediatric series among those published until now. The study series reported a shorter operative time, a higher success rate, and a lower postoperative complications rate compared with previous series. A limitation of this study is that stone-free rates may be somewhat inaccurate using ultrasonography and plain X-ray compared with computed tomography (CT); the study's 97.3% success rate may be overestimated because no CT scan was done postoperatively to check the stone-free rate. Other limitations of this article include its retrospective nature, the multi-institutional participation, and the heterogeneous patient collective. CONCLUSION: The Ho:YAG laser ureteroscopic lithotripsy seems to be an excellent first-line treatment for children with ureteral stones, independently from primary location and size. However, patients with proximal ureteral stones and residual fragments >2 mm reported a higher risk to require a secondary procedure to become stone-free. Combination of techniques as well as appropriate endourologic tools are key points for the success of the procedure regardless of stones' size and location

    Development Of Reciptures Of Canned Smothies Made From Zucchini And Fruits

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    Rational nutrition for a whole year is possible with a well-established system of storage and processing of plant raw materials. Products with vegetable and fruit raw materials due to their availability and nutritional value are in demand among the population. There is a constant interest in new products with increased biological value. The preservation of ascorbic acid, the main source of which is vegetables and fruits, is also affected by the technology of production. Despite the damaging effect of the heat treatment temperature of canned products on thermolabile components, the sterilization regimes should be relaxed. To this end, it has been proposed to produce beverages from vegetables and fruits for scientifically-based recipes, which allows them to be processed at a temperature of 100 °C, as well as juices with pulp and sugar. Smoothie, made on the basis of zucchini with the addition of gooseberries and blackcurrant puree contain respectively 13.3 and 41.8 mg/100 g of ascorbic acid, have an optimal for good perception of the sugar-acid index 21,4-21,5 compared with juices from soft pulp and sugar from gooseberry and black currant, which produces industry. The latter is explained by the fact that instead of sugar syrup, natural juice from zucchini was used in the recipe

    Kinetostatics of Wheel Vehicle in the Category of Spiral-Screw Routes

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    International audienceDeterministic mathematical model of kinetostatics of wheel vehicle in terms of different modes of spatial motion in the context of curved route is proposed. Earth-based coordinate system is introduced which pole and axial orientation are determined by the convenience of route description as well as vehicle-related coordinates which pole axial orientation are determined within inertial space with the help of natural trihedral. Turn of the natural trihedral within inertial coordinates is described by means of quaternion matrices in the context of Rodrigues-Hamilton parameters. Rodrigues-Hamilton parameters are in matrix form in direct accordance with specified hodograph. Kinetostatics of wheel vehicle is considered in terms of spatial motion with an allowance for three-dimensional aerodynamic forces, gravity, and tangential and centrifugal inertial forces. In the context of spiral-screw lines deterministic mathematical model of wheel vehicle kinetostatics is proposed in the form of hodograph in terms of uniform motion, accelerated motion, and decelerated motion within following route sections: straight and horizontal; in terms of vertical grade; in terms of horizontal plane. Analytical approach to determine animated contact drive-control forces of wheel vehicle for structural diagrams having one and two support points involving of a driving-driven wheel characteristic is proposed based on kinetostatics equations. Mathematical model of wheel vehicle kinetostatics in terms of spatial motion is constructed on the basis of nonlinear differential Euler-Lagrange equations; it is proposed to consider physically implemented motion trajectories of wheel vehicles in the context of spiral-screw lines; hodograph determines spatial displacement; Rodrigues-Hamilton parameters determines spatial turn; Varignon theorem is applied to identify components of drive (control) force. The obtained results make it possible to solve a wide range of problems connected with dynamic design of wheel vehicles involving controllability, and estimation of dynamic load of both system and support surface
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