345 research outputs found
Ion Beam Collimation for Future Hadron Colliders
The application of integrated simulation frameworks, which include particle tracking and physical interactions, to heavy-ion beam collimation in existing and future hadron colliders is presented. The SixTrack-FLUKA coupling and Beam Delivery Simulation (BDSIM) were used and the tools and techniques developed for the simulations are presented. A simulation study of the collimation cleaning inefficiency for heavy-ion beams was performed for the Large Hadron Collider (LHC), using both frameworks, and compared to measurements taken during operation. A detailed energy deposition study of ion beam collimation in a 3D model of the entire LHC ring was performed using BDSIM. The SixTrack-FLUKA coupling was used to study heavy-ion beam collimation in the Future Circular hadron- hadron Collider (FCC-hh). An analysis of the most limiting losses and an evaluation of the collimation system performance were carried out. The performance of the High-Energy Large Hadron Collider (HE-LHC) collimation system with heavy-ion beams was also investigated. The dominant beam loss clusters were identified and possible mitigation strategies are discussed. Support for partially stripped ions (PSI), which retain some of their bound electrons, was added to BDSIM and a physics model that treats charge-changing interactions of PSI with matter was implemented. Using the newly added features in BDSIM, the collimation of PSI beams in the LHC was studied in the context of the Gamma Factory initiative
Draft Genome Sequence of Lactobacillus fermentum Strain 3872
This report describes a draft genome sequence of Lactobacillus fermentum strain 3872. The data revealed remarkable similarity to and dissimilarity with the published genome sequences of other strains of the species. The absence of and variation in structures of some adhesins and the presence of an additional adhesin may reflect adaptation of the bacterium to different host systems and may contribute to specific properties of this strain as a new probiotic
Mechanism of Oxidative Stress in Neurodegeneration
Biological tissues require oxygen to meet their energetic demands. However, the consumption of oxygen also results in the generation of free radicals that may have damaging effects on cells. The brain is particularly vulnerable to the effects of reactive oxygen species due to its high demand for oxygen, and its abundance of highly peroxidisable substrates. Oxidative stress is caused by an imbalance in the redox state of the cell, either by overproduction of reactive oxygen species, or by dysfunction of the antioxidant systems. Oxidative stress has been detected in a range of neurodegenerative disease, and emerging evidence from in vitro and in vivo disease models suggests that oxidative stress may play a role in disease pathogenesis. However, the promise of antioxidants as novel therapies for neurodegenerative diseases has not been borne out in clinical studies. In this review, we critically assess the hypothesis that oxidative stress is a crucial player in common neurodegenerative disease and discuss the source of free radicals in such diseases. Furthermore, we examine the issues surrounding the failure to translate this hypothesis into an effective clinical treatment
Preservation of Soil Fertility Using Sidereal Clover
This study examined the use of intermediate groundcover sideral crops, such as perennial leguminous herbs, to conserve soil fertility though enriching the soil with fresh organic matter, an effective and low-cost method. Studies show that the use of direct sowing technology allows the preservation of all plant residues on the soil surface, which ensures the best accumulation of snow in the winter. Through the preservation of numerous biodrenes from the root system of sweet clover and other cultivated crops, as well as soil channels from earthworms, this direct sowing technology increases the moisture content of the soil and reduces moisture loss. The effectiveness of various soybean, corn and sunflower cultivation technologies with a minimal tillage period was studied. When sweet clover was used for green manure in April, the maximum yield was obtained, and the maximum yield for corn (57.3-82.3 c/ha) was obtained using the no-till technology. As a consequence, the ground cover crop had a noticeable effect on the yield of the second crop rotation - spring wheat, which had a higher yield. The use of direct sowing technology with sweet clover as green manure provided the highest yield of spring wheat - from 37.2 to 39.8 c / ha. The grain quality of spring wheat, placed as the second crop after melilot on green manure, was higher, both under no-till technology and under mini-till technology.
Keywords: biologization, soil fertility, green manure, clover, direct sowing, productivit
From 11% Thin Film to 23% Heterojunction Technology (HJT) PV Cell: Research, Development and Implementation Related 1600 × 1000 mm2 PV Modules in Industrial Production
Plasma-enhanced chemical vapor deposition (PECVD) developed for thin film (TF) Si:H-based materials resulted in large area thin film PV cells on glass and flexible substrates. However, these TF cells demonstrate low power conversion efficiency PCE = 11% for double and PCE = 13% for triple junction cells below predicted PCE ≈ 24%. PV cells on crystalline silicon (c-Si) provide PCE ≈ 17–19%. Cost of c-Si PV cells lowered continuously due to reducing price of silicon wafers and enlarging their size. Two factors stimulated a combination of PECVD films and c-Si devices: (a) compatibility of the technologies and (b) possibility for variation of electronic properties in PECVD materials. The latter results in additional build-in electric fields improving charge collection and harvesting solar spectrum. We describe a transformation of PECVD TF solar cell technology for 11% efficiency modules to heterojunction technology (HJT) c-Si modules with 23% efficiency. HJT PV structure comprises c-Si wafer with additional junctions created by PECVD deposited layers allowing development of single wafer PV cells with PCE ≈ 24% and the size limited by wafer (15.6 x 15.6 cm2). The chapter starts with background in PECVD and c-Si PV cells. Then, in Section 2, we describe electronic properties of PECVD materials in HJT PV structures. Section 3 deals with structure and fabrication process for HJT devices. In Section 4, we present and discuss performance characteristics of the devices. Section 5 describes implementation of the developed HJT module (1600 x 1000 mm2) based on HJT single wafer cells in industry with presentation and discussion of characteristics related to industrial production. Finally, Section 6 presents the outlook and summary of the chapter
Interaction of oxidative stress and misfolded proteins in the mechanism of neurodegeneration
Aggregation of the misfolded proteins β-amyloid, tau, huntingtin, and α-synuclein is one of the most important steps in the pathology underlying a wide spectrum of neurodegenerative disorders, including the two most common ones—Alzheimer's and Parkinson's disease. Activity and toxicity of these proteins depends on the stage and form of aggregates. Excessive production of free radicals, including reactive oxygen species which lead to oxidative stress, is proven to be involved in the mechanism of pathology in most of neurodegenerative disorders. Both reactive oxygen species and misfolded proteins play a physiological role in the brain, and only deregulation in redox state and aggregation of the proteins leads to pathology. Here, we review the role of misfolded proteins in the activation of ROS production from various sources in neurons and glia. We discuss if free radicals can influence structural changes of the key toxic intermediates and describe the putative mechanisms by which oxidative stress and oligomers may cause neuronal death
Carbon monoxide neurotoxicity is triggered by oxidative stress induced by ROS production from three distinct cellular sources
Carbon monoxide (CO) poisoning is one of the leading causes of toxic mortality and morbidity. We have studied the generation of reactive oxygen species in cortical neurons in culture in response to toxic doses of CO exposure. Fluorescence microscopy was used to measure the rate of free radical generation, lipid peroxidation, GSH level and also mitochondrial metabolism. We have found that toxic concentrations of CO released from CORM-401 induced mitochondrial depolarisation and inhibition of NADH dependent respiration to a lesser degree than when compared to ischaemia. Energy collapse was not observed within 40 min of CO exposure. We have found that CO induces the generation of reactive oxygen species resulting in lipid peroxidation and a decrease in GSH via three different mechanisms: from mitochondria during the first minutes of CO exposure, from xanthine oxidase at around 20 min exposure due to energy deprivation, and considerable ROS production from NADPH oxidase in the post CO exposure period (re-oxygenation). Inhibition of these different phases with mitochondrial antioxidants, inhibitors of xanthine oxidase, or NADPH oxidase, protected neurons and astrocytes against CO-induced oxidative stress and cell death. The most profound effect was seen during NADPH oxidase inhibition. Thus, oxidative stress has a remarkably significant role in CO-induced neuronal cell death and preventing its occurrence during reoxygenation is of great importance in the consideration of a positive, neurologically protective therapeutic outcome for CO exposed patients
Developing an algorithm for monitoring gas generators of hydrogen storage and supply systems
In relation to the main element of the hydrogen storage and supply system based on the hydro-reacting composition – the gas generator – an algorithm for its control has been developed. The development of such an algorithm is carried out in three stages. At the first stage, the problem of formalizing the hydrogen generation process is solved. Formalization of this process is carried out using the transfer function of the gas generator. The use of the criterion for the minimum error of the mismatch of the given amplitude-frequency characteristics of the gas generator allows to represent its transfer function in the form of a transfer function of the inertial link. At the second stage, the problem of determining the conditions for the occurrence of self-oscillations in the pressure stabilization subsystem is solved. A prerequisite for the emergence of a self-oscillating mode of operation of the hydrogen storage and supply system is the presence of a relay static characteristic of the pressure sensor. For the characteristic parameters of such a system, the ranges of values of the parameters of self-oscillations, frequencies and amplitudes, are determined. For these parameters, analytical expressions are obtained, which include the main parameters of the pressure stabilization subsystem in the hydrogen storage and supply system.
At the third stage, the problem of forming a gas generator control algorithm is solved. As a test action in the implementation of the control algorithm, self-oscillations in the pressure stabilization subsystem are used. The control algorithm for the gas generator of the hydrogen storage and supply system includes determining the parameters of self-oscillations and comparing their values with the values obtained a priori.
A typical diagram of a hydrogen storage and supply system is presented, in which the developed gas generator control algorithm is implemente
Draft genome sequence of Lactobacillus plantarum 2025
A draft genome sequence of Lactobacillus plantarum 2025 was derived using Ion Torrent sequencing technology. The total size of the assembly (3.33 Mb) was in agreement with the genome sizes of other strains of this species. The data will assist in revealing the genes responsible for the specific properties of this strain
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