480 research outputs found
Study of the switching characteristics of gas S-diodes
In the study, the switching properties of avalanche GaAs S-diodes are investigated. We studied diode assemblies of various configurations. It is shown that when using two or more diodes connected in series, the edge of the voltage pulse can be sharpened to about 1 ns
Evaluation of explosion influence on the waterproof rocks in shaft bottom area of Gremiachinsk mining and processing plant
The results of analytical studies of the explosion impact on the surrounding rock massif are presented. Explosion was performed during shaft bottom sinking of Gremiachinsk mining and processing plant. Safety parameters of explosion operations are determined to ensure continuity of the waterproof stratum (WPS), represented by three salt layers interbedded with anhydrite and dolomite rocks. In the calculations of slow motion explosion of blast hole charge it was simulated by explosion of single blast equal to the mass of blast material same kind but has bigger influence on rock massif than real blast hole explosion. Following are presented: the table with explosion parameters, chart and formulas for calculation of rock particles displacement rate in the explosion wave (mass rate) in relation with distance to explosion center in meters of relative units of distance. Wherein explosion influence on rock massif of small (or the same) charge simulate geometric similarity of real big scale explosion in well or blast hole at the distance bigger than well or blast hole length. The distance from explosion center measured in relative or specific value represented as sphere charge radiuses or length of edge of cubic charge of equal to the mass of real explosion. There is between these two different systems of distance measurement the set of rules of transition from one system to another for comparison of the results of different scale explosions.
In presence of transitional rules, coefficients in the formulas of explosion parameters are easily calculated depending on the distance to explosion center in particular for the most important destruction parameter of rock particles displacement rate in explosion wave. Dimensions of zones of various explosion effect on rock massif can also be expressed in any distance measurement system.
It is assumed in the article that in case of analogy of physical and mechanical properties of salt field rocks it is acceptable to use experimental results of the Verkhnekamsk field for similar studies of Gremiachinskoe field
Model of ionic currents through microtubule nanopores and the lumen
It has been suggested that microtubules and other cytoskeletal filaments may
act as electrical transmission lines. An electrical circuit model of the
microtubule is constructed incorporating features of its cylindrical structure
with nanopores in its walls. This model is used to study how ionic conductance
along the lumen is affected by flux through the nanopores when an external
potential is applied across its two ends. Based on the results of Brownian
dynamics simulations, the nanopores were found to have asymmetric inner and
outer conductances, manifested as nonlinear IV curves. Our simulations indicate
that a combination of this asymmetry and an internal voltage source arising
from the motion of the C-terminal tails causes a net current to be pumped
across the microtubule wall and propagate down the microtubule through the
lumen. This effect is demonstrated to enhance and add directly to the
longitudinal current through the lumen resulting from an external voltage
source, and could be significant in amplifying low-intensity endogenous
currents within the cellular environment or as a nano-bioelectronic device.Comment: 43 pages, 6 figures, revised versio
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
Дослідження напружено–деформованого стану елементів палуби контейнеровоза з використанням системи диференційних рівнянь Кармана
The current stage of development of the shipbuilding industry is characterized by the emergence of new types of ships, structurally significantly different from the traditional ones. In this connection, it is necessary to build more rigorous physical models describing the behavior of ship structures under the action of external loads.Structural mechanics of the ship, as an independent science, began to form at the beginning of the XX century. The founder of this science according to the rule can be considered a Russian scientist and shipbuilder, professor of the Naval Academy and the shipbuilding department of Petrograd Polytechnic Institute. Based on previous knowledge of the theory of elasticity to them the first rules of allowable stresses have been proposed for surface ships, the methods for evaluating the strength and stability of ship floors and reinforced plates were developed.Currently, structural mechanics of the ship faces a number of problems requiring urgent solutions, such as the desire for maximum reduction of body materials consumption, the emergence of new, more advanced manufacturing processes of the hull. To solve these problems, it is necessary to turn to the theoretical research and use the knowledge gained during the last three centuries, various scientists involved in various developments in the science of strength of materials, theory of elasticity, and theory of plasticity and structural mechanics of the ship.The importance of building effective and reliable calculation methods to predict the impact of the loading process on the long–term strength of structural materials is caused by the need to ensure long–term durability of structures in the conditions of insufficient and costly experimental studies.Container shipping today is the most convenient and the most universal means of transportation. A wide variety of types of containers (dry cargo, refrigerated, insulated, flat track, tank containers) ensures not only fast loading and unloading, but also the opportunity to use the maximum vessel capacity.The software system was studied and defined, which allows determining the deformation of the upper deck of the ship while loading and on the resulting chart voltages to determine possible locations of damage with the aim of preventing them, because any accident on the ship can not only cause human and material losses, but also major environmental disasters.The practical value of the results of the work lies in the fact that these studies make it possible to assess the actual loading of shipbuilding structures in terms of their operation.Рассматриваются современные методы и средства решения задачи расчета напряженно–деформированного состояния палубных элементов судов. Проведен анализ современных методов оценки напряженно–деформированного состояния судовых пластин на стадии проектирования и эксплуатации судна. Для этого в качестве обзора рассмотрены основные программные комплексы, позволяющие проводить подобные расчеты, их положительные и отрицательные стороны. Приведены основные этапы создания программного обеспечения для проведения расчетов, основанных на использовании системы Кармана.Розглядаються сучасні методи і засоби вирішення задачі розрахунку напружено–деформованого стану палубних елементів суден. Проведено аналіз сучасних методів оцінки напружено–деформованого стану суднових пластин на стадії проектування і експлуатації судна. Для цього в якості огляду розглянуті основні програмні комплекси, що дозволяють проводити подібні розрахунки, їх позитивні і негативні сторони. Наведені основні етапи створення програмного забезпечення для проведення розрахунків, заснованих на використанні системи Кармана
Using specification-based intrusion detection for automated response
Abstract. One of the most controversial issues in intrusion detection is automating responses to intrusions, which can provide a more efficient, quicker, and precise way to react to an attack in progress than a human. However, it comes with several disadvantages that can lead to a waste of resources, which has so far prevented wide acceptance of automated response-enabled systems. We feel that a structured approach to the problem is needed that will account for the above mentioned disadvantages. In this work, we briefly describe what has been done in the area before. Then we start addressing the problem by coupling automated response with specification-based, host-based intrusion detection. We describe the system map, and the map-based action cost model that give us the basis for deciding on response strategy. We also show the process of suspending the attack, and designing the optimal response strategy, even in the presence of uncertainty. Finally, we discuss the implementation issues, our experience with the early automated response agent prototype, the Automated Response Broker (ARB), and suggest topics for further research.
ИсслЕдованиЕ напряженнО–дефОрмирОваннОгО состоЯниЯ элементоВ палубЫ контейнеровозА С использованиеМ системЫ дифференциальныХ уравнениЙ КАрмАнА
Рассматриваются современные методы и средства решения задачи расчета напряженно–деформированного состояния палубных элементов судов. Проведен анализ современных методов оценки напряженно–деформированного состояния судовых пластин на стадии проектирования и эксплуатации судна. Для этого в качестве обзора рассмотрены основные программные комплексы, позволяющие проводить подобные расчеты, их положительные и отрицательные стороны. Приведены основные этапы создания программного обеспечения для проведения расчетов, основанных на использовании системы Кармана
Phylogeny and Fatty Acid Profiles of New Pinnularia (Bacillariophyta) Species from Soils of Vietnam
We studied the morphology, ultrastructure, and phylogeny of eight soil diatom strains assigned to the Pinnularia genus. Six of these strains, identified by us as new species, are described for the first time. We provide a comprehensive comparison with related species and include ecological data. Molecular phylogeny reconstruction using 18S rDNA and rbcL affiliates the new strains with different subclades within Pinnularia, including ‘borealis’, ‘grunowii’ and ‘stomatophora’. We also studied the fatty acid profiles in connection with the emerging biotechnological value of diatoms as a source of lipids. Stearic (36.0–64.4%), palmitic (20.1–30.4%), and palmitoleic (up to 20.8%) acids were the dominant fatty acids in the algae cultured on Waris-H + Si medium. High yields of saturated and monounsaturated fatty acids position the novel Pinnularia strains as a promising feedstock for biofuel production
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