Contact ureterolithotripsy of a giant ureteral stone in a 3-year-old child

Giant ureteral stones in young children are extremely rare and their surgical treatment tactics are variable. The present case describes a case of effective and safe endoscopic treatment of giant ureteral stones in a young child. The patient is a 3-year-old male child. Examination findings of abdominal pain and fever verified a left distal ureteric stone up to 30 mm complicated by ureterohydronephrosis. The first treatment stage was ureteral stenting, in which the stone migrated to the middle ureteral third. The second treatment stage was contact ureterolithotripsy with a 9 Ch semi-rigid ureteroscope («Richard Wolf» GmbH, Knittlingen, Germany) and Swiss LithoClast® 2 pneumatic lithotripter («E.M.S. Electro Medical Systems» S.A., Nyon, Suisse), ureteral stenting (2-way PigTail, 4.5 Ch). The third treatment stage in the delayed period was extracorporeal shockwave lithotripsy of the steinstrasse using the Dornier Compact Sigma («Dornier MedTech» GmbH, Weßling, Germany) and stent removal. Residual stones were not revealed according to the follow-up examination. No treatment complications were registered. The multimodal staged treatment of a giant ureteral stone resulted in its complete elimination. Next-step ureteral endoscopy made it possible to identify concomitant pathology of the proximal ureter, which required its evaluation in the delayed period. Ureteral stenting contributed to the restoration of renal function. The result achieved reflects the maximum efficiency and high safety of the surgical technique applied

Josephson array of mesoscopic objects. Modulation of system properties through the chemical potential

The phase diagram of a two-dimensional Josephson array of mesoscopic objects is examined. Quantum fluctuations in both the modulus and phase of the superconducting order parameter are taken into account within a lattice boson Hubbard model. Modulating the average occupation number $n_0$ of the sites in the system leads to changes in the state of the array, and the character of these changes depends significantly on the region of the phase diagram being examined. In the region where there are large quantum fluctuations in the phase of the superconducting order parameter, variation of the chemical potential causes oscillations with alternating superconducting (superfluid) and normal states of the array. On the other hand, in the region where the bosons interact weakly, the properties of the system depend monotonically on $n_0$. Lowering the temperature and increasing the particle interaction force lead to a reduction in the width of the region of variation in $n_0$ within which the system properties depend weakly on the average occupation number. The phase diagram of the array is obtained by mapping this quantum system onto a classical two-dimensional XY model with a renormalized Josephson coupling constant and is consistent with our quantum Path-Integral Monte Carlo calculations.Comment: 12 pages, 8 Postscript figure

Tagging High Energy Photons in the H1 Detector at HERA

Measures taken to extend the acceptance of the H1 detector at HERA for photoproduction events are described. These will enable the measurement of electrons scattered in events in the high y range 0.85 < y < 0.95 in the 1998 and 1999 HERA run period. The improvement is achieved by the installation of an electromagnetic calorimeter, the ET8, in the HERA tunnel close to the electron beam line 8 m downstream of the H1 interaction point in the electron direction. The ET8 will allow the study of tagged gamma p interactions at centre-of-mass energies significantly higher than those previously attainable. The calorimeter design and expected performance are discussed, as are results obtained using a prototype placed as close as possible to the position of the ET8 during the 1996 and 1997 HERA running.Comment: 13 pages, 13 figure

A New High Energy Photon Tagger for the H1 - Detector at HERA

The H1 detector at HERA has been upgraded by the addition of a new electromagnetic calorimeter. This is installed in the HERA tunnel close to the electron beam line at a position 8m from the interaction point in the electron beam direction. The new calorimeter extends the acceptance for tagged photoproduction events to the high y range, 0.85 < y < 0.95, and thus significantly improves the capability of H1 to study high energy gamma-p processes. The calorimeter design, performance and first results obtained during the 1996-1999 HERA running are described.Comment: 17 pages, 16 figure

New model for system of mesoscopic Josephson contacts

Quantum fluctuations of the phases of the order parameter in 2D arrays of mesoscopic Josephson junctions and their effect on the destruction of superconductivity in the system are investigated by means of a quantum-cosine model that is free of the incorrect application of the phase operator. The proposed model employs trigonometric phase operators and makes it possible to study arrays of small superconducting granules, pores filled with superfluid helium, or Josephson junctions in which the average number of particles $n_0$ (effective bosons, He atoms, and so on) is small, and the standard approach employing the phase operator and the particle number operator as conjugate ones is inapplicable. There is a large difference in the phase diagrams between arrays of macroscopic and mesoscopic objects for $n_0 < 5$ and $U<J$ ($U$ is the characteristic interaction energy of the particle per granule and $J$ is the Josephson coupling constant). Reentrant superconductivity phenomena are discussed.Comment: 4 pages, 3 Postscript figure

Tо Ecological Monitoring of Self- Propelled Field Sprinklers

An improved method for making a decision on choosing the best self-propelled sprayer from alternative options is proposed. It refers to new developments in various fields of environmental monitoring and analysis of field self-propelled sprinklers, but which substantiate the studied factors characterizing each unit. The factors are taken with real values of calculated parameters, for which the desirability function and weighty coefficients are developed using the method of pairwise comparison of calculated parameters of absolute and relative rank places and the percentile function. The dependence of the transfer of calculated parameters of the unit from real values to dimensionless ones for the y’ scale is clarified, according to which the desirability function is calculated, and then a generalized parameter characterizing the complex evaluation of the unit in respect to the weighting coefficient of each estimated parameter. The decision is made according to the maximum value of the parameters of integrated assessment of the sprinkler, in this task for the sprinkler TUMAN-1 (Russia), for which the value of the parameter of integrated assessment is obtained

High-aspect ratio probes with selected geometry for advanced MFM measurements

The authors appreciate financial support by Ministry of Education and Science of the Russian Federation, Russia, State Project № 075-00780-19-00, Subject № 0074-2019-0007