Simulation of Radiation Damage to Neural Cells with the Geant4-DNA Toolkit

To help in understanding the physical and biological mechanisms underlying effects of cosmic and therapeutic types of radiation on the central nervous system (CNS), we have developed an original neuron application based on the Geant4 Monte Carlo simulation toolkit, in particular on its biophysical extension Geant4-DNA. The applied simulation technique provides a tool for the simulation of physical, physico-chemical and chemical processes (e.g. production of water radiolysis species in the vicinity of neurons) in realistic geometrical model of neural cells exposed to ionizing radiation. The present study evaluates the microscopic energy depositions and water radiolysis species yields within a detailed structure of a selected neuron taking into account its soma, dendrites, axon and spines following irradiation with carbon and iron ions

Reactive SPS of Al2O3–RE:YAG (RE = Ce; Ce+Gd) composite ceramic phosphors

Ultrafine-grained Al2O3–rare earth:yttrium aluminium garnet (Al2O3–RE:YAG) (RE = Ce; Ce+Gd) composite ceramics were obtained for the first time by reactive spark plasma sintering (SPS) using commercially available initial oxide powders. The effect of key sintering parameters (temperature, dwell time, and external pressure (Pload)) on densification peculiarities, structural-phase states, and luminescent properties of composites was studied comprehensively. Differences in phase formation and densification between Ce-doped and Ce,Gd-codoped systems were shown. Parameters of reactive SPS, at which there is partial melting with the formation of near-eutectic zones of the Al2O3–YAG system/coexistence of several variations of the YAG-type phase, were established. Pure corundum–garnet biphasic ceramics with an optimal balance between microstructural and luminescence performance were synthesized at 1425 ℃/30 min/30–60 MPa. The external quantum efficiency (EQE) of the phosphor converters reached 80.7% and 72% with close lifetime of ~63.8 ns, similar to those of commercial Ce:YAG materials, which is promising for further applications in the field of high-power white light-emitting diodes (WLEDs) and laser diodes (LDs)

About optimal geometric parameters of a developed I-beam with a perforated web

For the first time, questions of optimization of geometric parameters of developed I-beam with a perforated web are considered with the use of the finite element method in PC ANSYS Mechanical. For the linear model of the material, strength and stiffness calculations are performed depending on the shape of the cut: the height of the I-beam development and the distance between the holes. For the I-beam with the highest height, the stability of the web was checked, the first two critical loads and forms of stability loss were obtained. The optimum degree of development is shown on the example of the 12-meter developed I-beam from the initial rolled I-beam with a height of 60 cm. The strength and rigidity of the beam is determined when the length of the distance between the holes is changed

About optimal geometric parameters of a developed I-beam with a perforated web

For the first time, questions of optimization of geometric parameters of developed I-beam with a perforated web are considered with the use of the finite element method in PC ANSYS Mechanical. For the linear model of the material, strength and stiffness calculations are performed depending on the shape of the cut: the height of the I-beam development and the distance between the holes. For the I-beam with the highest height, the stability of the web was checked, the first two critical loads and forms of stability loss were obtained. The optimum degree of development is shown on the example of the 12-meter developed I-beam from the initial rolled I-beam with a height of 60 cm. The strength and rigidity of the beam is determined when the length of the distance between the holes is changed

Plasma activated water for an eco sustainable management and defense of agricultural crops

Al giorno d'oggi una delle principali sfide è quella di muoversi verso un'agricoltura eco-sostenibile, in grado di preservare la produzione alimentare attraverso un uso limitato di sostanze chimiche. Attualmente, il sostentamento alimentare globale è raggiunto, quasi esclusivamente, mediante un'agricoltura intensiva basata principalmente sulla monocoltura delle colture più redditizie. Questo approccio riduce drasticamente la biodiversità promuovendo, nelle piante, il manifestarsi di svariati stress di origine abiotica e biotica generalmente controllati mediante un cospicuo impiego di pesticidi. Per promuovere una gestione eco-sostenibile delle malattie delle piante e fornire una metodologia totalmente innovativa, è stata applicata, in campo ed in laboratorio, una nuova tecnologia basata sull'utilizzo di acqua attivata dal plasma (PAW). Questa soluzione, caratterizzata dalla presenza al suo interno di specie reattive dell'ossigeno e dell'azoto in ambiente acido, è stata impiegata con l’obiettivo di migliorare le risposte di difesa delle piante. I risultati, ottenuti su diverse piante (pervinche-viti) e condizioni di crescita (vitro-vivo), indicano l’abilità di PAW nel migliorare le risposte di difesa delle piante sia a livello trascrizionale che post-trascrizionale. Questo stimolo, indotto dalla presenza di forme reattive di ossigeno e azoto in soluzione, genera inoltre la sintesi di importanti composti antiossidanti impiegati nell’industria farmaceutica. Infine, l’applicazione di PAW direttamente in campo ha evidenziato come queste proprietà, dimostrate in laboratorio, abbiano portato ad una riduzione di piante positive alla presenza di fitoplasmi e all’aumento dei loro parametri quantitativi di resa.Nowadays one of the main challenges is moving towards an eco-sustainable agriculture, able to preserve the food production through a limited chemicals use. Currently, a global food sustenance is achieved by intensive agriculture mainly based on economic crops monoculture. This approach drastically reduces the biodiversity increasing yield losses due to biotic and abiotic stress and leads to massive use of pesticides. To ensure yield stability and to promote an eco-sustainable management of plant diseases, a new technology based on plasma activated water (PAW), characterized by reactive oxygen and nitrogen species in acid environment, was applied to enhance plant resistance responses. Our results, obtained on different plants (periwinkles- grapevines) and growth conditions (vitro-vivo), indicate that PAW enhances plant defence responses at both, transcriptional and post-transcriptional level, leading likely to the synthesis of anti-oxidant compounds employed in the pharmaceutical industry. Furthermore, in vineyards these effects resulted on reduction of phytoplasma-positive plants and on increasing of quantitative yield parameters

Simulation of Radiation Damage to Neural Cells with the Geant4-DNA Toolkit

To help in understanding the physical and biological mechanisms underlying effects of cosmic and therapeutic types of radiation on the central nervous system (CNS), we have developed an original neuron application based on the Geant4 Monte Carlo simulation toolkit, in particular on its biophysical extension Geant4-DNA. The applied simulation technique provides a tool for the simulation of physical, physico-chemical and chemical processes (e.g. production of water radiolysis species in the vicinity of neurons) in realistic geometrical model of neural cells exposed to ionizing radiation. The present study evaluates the microscopic energy depositions and water radiolysis species yields within a detailed structure of a selected neuron taking into account its soma, dendrites, axon and spines following irradiation with carbon and iron ions

Simulation of Radiation Damage to Neural Cells with the Geant4-DNA Toolkit

To help in understanding the physical and biological mechanisms underlying effects of cosmic and therapeutic types of radiation on the central nervous system (CNS), we have developed an original neuron application based on the Geant4 Monte Carlo simulation toolkit, in particular on its biophysical extension Geant4-DNA. The applied simulation technique provides a tool for the simulation of physical, physico-chemical and chemical processes (e.g. production of water radiolysis species in the vicinity of neurons) in realistic geometrical model of neural cells exposed to ionizing radiation. The present study evaluates the microscopic energy depositions and water radiolysis species yields within a detailed structure of a selected neuron taking into account its soma, dendrites, axon and spines following irradiation with carbon and iron ions

Stochastic Processes Occurring during the Transition of Technical State of the Structure

The possibility of applying the theory of stochastic processes for evaluating the dynamic pattern of different states is studied for critical-duty structures. Heterogeneous Markovian processes of technical state transition for metallurgical overhead crane structure, Markovian theorem and Kolmogorov-Chapman equation are analyzed. Markovian chain is reviewed at t →∞, i.e. under marginal steady-state (stabilized) condition. Real values of limit probabilities are obtained for the structure of the metallurgical overhead crane under review. The proposed approach redefines and elaborates the existing methods and procedures for evaluating the technical state of structures and reduces the level of ambiguity associated with such kind of problems

Nonlinear Dynamics of Heavy Structures

At the moment, not enough attention is paid to different aspects of nonlinear dynamics for heavy structures. In this article we attempt to create a mathematical model for finding a frame (field) with predictable dynamic pattern of load-carrying capability for a heavy structure based оn the parameters of its reliable (failure-free, low-risk) operation. It is difficult to find a solution for this problem now but the following algorithm can be applied. Small dimension projection is first obtained for orthonormal vectors determining the structural load-carrying capability. Then we use available methods to find a field where any relationship (functional, logical) can be obtained between the rules (wild cards) and the load-carrying capability displayed by a heavy structure. This article carries on the cycle of activities on structural risk analysis involving heavy structures. Numerical and calculated data are based on previous studies. The analysis is performed on a metallurgical overhead crane. The obtained findings are used for adopting various engineering solutions at different stages of heavy structure operation