316 research outputs found
Assessment of operational reliability of quarry excavator-dump truck complexes
The method proposed in the article is based on the mathematical apparatus for quantitative assessment of the reliability of majority schemes of structural redundancy of transport processes, which provide the availability and usage of several backup delivery channels in the transport process in case of any malfunction. The principle of multi-channel haulage is commonly used in quarries for transportation of overburden and minerals from benches by dump trucks, when excavators and dump trucks performing cyclic operations function as a single excavator-dump truck complex. This pattern of work significantly increases the likelihood of fulfilling the daily plan for transporting rock mass due to the redistribution of dump trucks between mining and overburden excavators in the event of failure of one or more units of mining and handling equipment.
The reliability of excavator-dump truck complexes is assessed in three stages: initial data collection for mathematical modeling of excavator-dump truck complex performance; solving the problem of optimizing the distribution of dump trucks between excavators, ensuring maximum productivity of the excavator-dump truck complex; assessment of the reliability of its work depending on the probability of fulfilling the daily plan for the transportation of rock mass.
The proposed method is implemented as part of a computer program and makes it possible to automate the operational management of the process of transporting rock mass in a quarry using a mobile application. The developed guidelines can be used for any quarries with automobile transport, regardless of the type of mineral extracted, the mining method, the loading pattern, the capacity of the excavation and loading equipment fleet, and the capacity of operated dump trucks
Identity of electrons and ionization equilibrium
It is perhaps appropriate that, in a year marking the 90th anniversary of
Meghnad Saha seminal paper (1920), new developments should call fresh attention
to the problem of ionization equilibrium in gases. Ionization equilibrium is
considered in the simplest "physical" model for an electronic subsystem of
matter in a rarefied state, consisting of one localized electronic state in
each nucleus and delocalized electronic states considered as free ones. It is
shown that, despite the qualitative agreement, there is a significant
quantitative difference from the results of applying the Saha formula to the
degree of ionization. This is caused by the fact that the Saha formula
corresponds to the "chemical" model of matter.Comment: 9 pages, 2 figure
A deep learning method based on language models for processing natural language Russian commands in human robot interaction
This paper describes the transformation process complex Russian-speaking natural language commands into a formalized graph RDF format for interaction with the robotic platfor
Quantum oscillations of nitrogen atoms in uranium nitride
The vibrational excitations of crystalline solids corresponding to acoustic
or optic one phonon modes appear as sharp features in measurements such as
neutron spectroscopy. In contrast, many-phonon excitations generally produce a
complicated, weak, and featureless response. Here we present time-of-flight
neutron scattering measurements for the binary solid uranium nitride (UN),
showing well-defined, equally-spaced, high energy vibrational modes in addition
to the usual phonons. The spectrum is that of a single atom, isotropic quantum
harmonic oscillator and characterizes independent motions of light nitrogen
atoms, each found in an octahedral cage of heavy uranium atoms. This is an
unexpected and beautiful experimental realization of one of the fundamental,
exactly-solvable problems in quantum mechanics. There are also practical
implications, as the oscillator modes must be accounted for in the design of
generation IV nuclear reactors that plan to use UN as a fuel.Comment: 25 pages, 10 figures, submitted to Nature Communications,
supplementary information adde
Non-destructive detection of cross-sectional strain and defect structure in an individual Ag five-fold twinned nanowire by 3D electron diffraction mapping
Coherent x-ray diffraction investigations on Ag five-fold twinned nanowires (FTNWs) have drawn controversial conclusions concerning whether the intrinsic 7.35° angular gap could be compensated homogeneously through phase transformation or inhomogeneously by forming disclination strain field. In those studies, the x-ray techniques only provided an ensemble average of the structural information from all the Ag nanowires. Here, using three-dimensional (3D) electron diffraction mapping approach, we non-destructively explore the cross-sectional strain and the related strain-relief defect structures of an individual Ag FTNW with diameter about 30 nm. The quantitative analysis of the fine structure of intensity distribution combining with kinematic electron diffraction simulation confirms that for such a Ag FTNW, the intrinsic 7.35° angular deficiency results in an inhomogeneous strain field within each single crystalline segment consistent with the disclination model of stress-relief. Moreover, the five crystalline segments are found to be strained differently. Modeling analysis in combination with system energy calculation further indicates that the elastic strain energy within some crystalline segments, could be partially relieved by the creation of stacking fault layers near the twin boundaries. Our study demonstrates that 3D electron diffraction mapping is a powerful tool for the cross-sectional strain analysis of complex 1D nanostructures
Telomerase inhibition improves tumor response to radiotherapy in a murine orthotopic model of human glioblastoma
NOVOSIBIRSK REGION PROGRAM OF THE LIVER TRANSPLANTATION IN CHILDREN
The aim of the study was to analyze the early and late outcomes of pediatric liver transplantation (LTx) program in the Novosibirsk region. Material and Methods. The retrospective study included 24 patients aged 72 ± 74.8 months (from 4 to 212 months, median – 20 months) with a body weight of 21.7 ± 18.1 kg (from 4.5 to 55 kg, median – 12.5 kg). Two (8.3 %) cadaveric whole liver grafts, 19 (79.2 %) living donor liver grafts, and 3 (12.5 %) cadaveric liver fragments (reduced-size or split-liver) were transplanted. Results. The features of vascular and biliary reconstruction in different types of LTx are discussed. The incidence of vascular and biliary complications was 8.3 and 20.8%, respectively. The patients stayed in the intensive care unit for 9 ± 5.1 days (from 4 to 22 days, median 8 days) and total length of hospital stay was for 40 ± 25.4 days (from 19 to 136 days, median 32 days). Two (8.3 %) recipients had early graft dysfunction. Perioperative mortality (up to 90 days) was absent. The overall 5-year patient and graft survival rates were 95 and 88 %, respectively. Conclusion. The Novosibirsk region has a pediatric LTx program with outcomes comparable to the data of the leading world and Russian centers
Telomerase expression and telomere length in breast cancer and their associations with adjuvant treatment and disease outcome
- …