Stress-strain state of the mine massif around the chambers of the second stage of mining

A stress-strain state of the rock mass around the chambers of the second stage of mining was analyzed with the help of thermodynamic method. This study is the question of the day as the ore reserves in the chambers of the second stage of mining are, as a rule, extracted being surrounded by the filling mass, and due to this the highest rates of the ore losses and contamination with the filling mass are observed. In connection with this, the study of the stress-strained state of the filling mass and establishment of a method for improving the massif stability presents a great interest today. A calculation scheme for modeling thermodynamic processes in the rock mass around the chambers was developed with the purpose to study the stress field and determine principles of radial stress changing in the filling mass of the surrounding chamber. A chamber in the layer at the depth of 740-840 m was simulated with the following average geotechnical conditions: depth of the extraction chamber, angle of the deposit depression, horizontal thickness of deposit, rock strength in the hanging layer against uniaxial compression, rock strength in the bottom layer against uniaxial compression, and stowing strength against uniaxial compression. The study determined areas with tensile stress in the rocks of the bottom layer, ore mass and filling mass, and their parameters (size, maximum tension) and formulated empirical equations for the dependences between radial tensions and distance to the chambers L of the second stage of mining. The areas of destructive deformation and their dimensions in the stowing mass around the chambers of the second stage of mining at the level 740-840 m were established. Maximum values are defined for the stresses acting in the stowing mass which, exceeding the ultimate strength, cause the mass failure into the space of the chamber of the second stage. In order to prevent the stowing mass failure it is recommended to make a consolidating layer of the solid stowing at the 2/3 height of the chamber in order to resist the high tensile stresses and to ensure the mass stability

Role of the molybdenum addition on the mechanical properties and structure of the NiCoMnIn alloys

In this paper, the influence of Mo addition on the structure and mechanical properties of the NiCoMnIn alloys have been studied. Series of polycrystalline NiCoMnIn alloys containing from 0 to 5 mas.% of Mo were produced by the arc melting technique. For the alloys containing Mo, two-phase microstructure was observed. Mo-rich precipitates were distributed randomly in the matrix. The relative volume fraction of the precipitates depends on the Mo content. The numbers of the Mo rich precipitates increases with the Mo contents. The structures of the phases were determined by the TEM. The mechanical properties of the alloys are strongly affected by Mo addition contents. Brittleness of the alloys increases with the Mo contents

Remote Sensing Data Visualization, Fusion and Analysis via Giovanni

We describe Giovanni, the NASA Goddard developed online visualization and analysis tool that allows users explore various phenomena without learning remote sensing data formats and downloading voluminous data. Using MODIS aerosol data as an example, we formulate an approach to the data fusion for Giovanni to further enrich online multi-sensor remote sensing data comparison and analysis

The Effect of Physiological Performance Variables on 3000m Times in Collegiate Mid-Distance and Distance Runners

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Characteristics of the expression level of E-Cadherin and ß-Catenin in hepatocellular and cholangiocellular liver carcinoma

Aim. In order to determine the level of immunohistochemical expression of E-cadherin and β-catenin in hepatocellular and cholangiocellular liver cancer of different diameters and areas of the immunopositive cells trephine biopsies of liver of 94 patients were studied, among them 55 (58.51%) had hepatocellular carcinoma (HCC) and 39 (41.49%) had cholangiocellular liver cancer (CCC). Methods and results. Considering the size of the tumor determined by ultrasound examination of the liver 21 HCC and 17 CCC less than5 cmin diameter, and 34 HCC and 22 CCC with diameter more than 5 cm were assayed. The expression of E-cadherin by cells was determined using a monoclonal antibody Mo-Hu E -Cadherin, Clone NCH-38, and the expression of β-catenin - using monoclonal antibodies Mo a Hu Beta-Catenin, Clone E247 ß-Catenin-1. The level of expression of immunohistochemical markers of tumor cells and immunopositive tumor cells area were determined by photo digital morphometry in digital image processing program Image J. It was found that in 63,64% of patients with HCC and 100% of patients with CCC, liver cancer cells show membrane or membrane-cytoplasmic expression of E-cadherin. E-cadherin immunopositive cells make up 42,25±15,12% of area of HCC tissue section and 35,13±15,69% of area of liver tissue section of CCC. In the 94,55% of HCC cases and 100% of patients with CCC membrane expression of β-catenin, combined with a nuclear or cytoplasmic expression of the protein, was revealed in tumor cells. β-catenin immunopositive cells make up 62,39±20,41% of area of HCC tissue section and 55,83±19,67% of area of liver tissue section in CCC. In HCC and CCC, between low expression of E-cadherin by tumor cells and high levels of β-catenin a direct strong correlation is observed. In large HCC and CCC compared with smaller tumors up to5 cmin diameter, significantly smaller space was occupied by E-cadherin-immunopositive cells and larger area was occupied by β-catenin-immunopositive cells. Conclusion. The comparison of the expression of adhesively-migration markers by tumor cells shows that hepatocellular carcinoma and cholangiocellular cancer are characterized by early loss of intercellular adhesion bonds and high potencies to invasive growth in the liver

Effects of electromagnetic fields emitted by GSM phones on working memory: a meta-analysis

Background and Objective: Current treatments for Alzheimer's Disease (AD) do not affect the course of the illness and brain stimulation techniques are increasingly promoted as potential therapeutic inter-ventions for AD. This study reviews the effects of electromagnetic field (EMF) exposure versus sham exposure on working memory (WM) performance of healthy human participants. Method: Online literature databases and previous systematic reviews were searched for studies of EMF and WM in participants without reported memory problems. Two thousand eight hundred and fifty seven studies were identified, and 10 studies met the inclusion criteria. An assessment of study quality was completed, and separate, random effects meta-analyses were conducted for each of the three WM tasks included: n-back, substitution and digit span forward. Results: No differences were found between participants exposed to active EMF versus sham conditions in any of the three working memory tasks examined. Conclusion: Results indicate that EMF does not affect WM during the n-back, substitution and digit-span tasks. Future studies should focus on the possible effects of chronic exposure to EMF in older adults with AD using a battery of comparable WM and attention tasks, before EMF can be seriously considered as a potential modulator of WM in AD

Crystal structure of the high temperature phase of strontium barium niobate

Pure and undoped strontium-barium niobate Sr0:40Ba0:60Nb2O6 (SBN40) single crystals grown by the Czochralski method were investigated by single crystal X-ray diffraction methods. The study below TC (429 K for SBN40) confirmed the structure with P4bm space group. Above this temperature the structure transforms into the paraelectric, centrosymmetric one with P4=mbm space group. Analysis of the recorded diffraction patterns allowed to observe several signs of crystal structure modulation. On the registered diffraction images satellite reflections were found. A modulation vector q = ( ; ; ), where = 0:3075(6) (at room temperature) was found and it was similar to that occurring in the SBN61. In addition, above the phase transition temperature on the (hk) planes with l integer a weak diffuse scattering was observed

Diodes with Breakdown Voltages Enhanced by the Metal-Insulator Transition of LaAlO3_3-SrTiO3_3 Interfaces

Using the metal-insulator transition that takes place as a function of carrier density at the LaAlO$_3$-SrTiO$_3$ interface, oxide diodes have been fabricated with room-temperature breakdown voltages of up to 200 V. With applied voltage, the capacitance of the diodes changes by a factor of 150. The diodes are robust and operate at temperatures up to 270 C