Chapter 8: Perspectives for the use of biological indicators for the assessment of radiation induced responses and impairments: The use of biological indicators to assess consequences of radiation exposure at the cell system level. Report of a panel discussion under the chairmanship ofW. Gössner

Stem Cells ◽  
1995 ◽  
Vol 13 (S1) ◽  
pp. 323-325 ◽  
Author(s):  
C. Selig
Keyword(s):  
Radiation Exposure ◽  
Panel Discussion ◽  
Biological Indicators ◽  
Cell System ◽  
System Level ◽  
Induced Responses ◽  
Radiation Induced

Modeling of a Direct Carbon Fuel Cell System

2010 ◽  
Vol 7 (5) ◽  
Author(s):  
K. Hemmes ◽  
M. Houwing ◽  
N. Woudstra
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Exergy Analysis ◽  
Cell System ◽  
System Model ◽  
System Level ◽  
Molten Carbonate ◽  
Bench Scale ◽  
Direct Carbon Fuel Cell ◽  
Molten Carbonate Fuel Cells

Direct carbon fuel cells (DCFCs) have great thermodynamic advantages over other high temperature fuel cells such as molten carbonate fuel cells (MCFCs) and solid oxide fuel cells. They can have 100% fuel utilization, no Nernst loss (at the anode), and the CO2 produced at the anode is not mixed with other gases and is ready for re-use or sequestration. So far, only studies have been reported on cell development. In this paper, we study the performance of a CO2-producing DCFC system model. The theoretically predicted advantages that are confirmed on a bench scale are also confirmed on a system level, except for the production of pure CO2. Net system efficiencies of around 78% were found for the developed system. An exergy analysis of the system shows where the losses in the system occur. If the cathode of the DCFC must be operated as a standard MCFC cathode, the required CO2 at the cathode is the reason why a large part of the pure CO2 from the anode is recycled and mixed with the incoming air and cannot be used directly for sequestration. Bench scale studies should be performed to test the minimum amount of CO2 needed at the cathode. This might be lower than in a standard MCFC operation due to the pure CO2 at the anode side that enhances diffusion toward the cathode.

Metaphase-Based Cytogenetic Approach Identifies Radiation-Induced Chromosome and Chromatid Aberrations in Zebrafish Embryos

2021 ◽  
Author(s):  
Halida Thanveer Asana Marican ◽  
Hongyuan Shen
Keyword(s):  
Animal Model ◽  
Radiation Exposure ◽  
Progenitor Cells ◽  
Chromosome Aberrations ◽  
Structural Changes ◽  
Current Knowledge ◽  
Living Organism ◽  
Zebrafish Embryos ◽  
Radiation Induced

Metaphase-based cytogenetic methods based on scoring of chromosome aberrations for the estimation of the radiation dose received provide a powerful approach for evaluating the associated risk upon radiation exposure and form the bulk of our current knowledge of radiation-induced chromosome damages. They mainly rely on inducing quiescent peripheral lymphocytes into proliferation and blocking them at metaphases to quantify the damages at the chromosome level. However, human organs and tissues demonstrate various sensitivity towards radiation and within them, self-proliferating progenitor/stem cells are believed to be the most sensitive populations. The radiation-induced chromosome aberrations in these cells remain largely unknown, especially in the context of an intact living organism. Zebrafish is an ideal animal model for research into this aspect due to their small size and the large quantities of progenitor cells present during the embryonic stages. In this study, we employ a novel metaphase-based cytogenetic approach on zebrafish embryos and demonstrate that chromosome-type and chromatid-type aberrations could be identified in progenitor cells at different cell-cycle stages at the point of radiation exposure. Our work positions zebrafish at the forefront as a useful animal model for studying radiation-induced chromosome structural changes in vivo.

Changes in the Cortex Neurons in Single and Fractional Gamma Radiation

2021 ◽  
Vol 66 (4) ◽  
pp. 18-24
Author(s):  
I. Ushakov ◽  
Vladimir Fyodorov
Keyword(s):  
Nervous System ◽  
Cerebral Cortex ◽  
Radiation Exposure ◽  
Comparative Assessment ◽  
Male Rats ◽  
Fractionated Irradiation ◽  
Radiation Induced ◽  
Post Radiation ◽  
Induced Changes ◽  
The Brain

Purpose: Comparative assessment of radiation-induced changes in neurons of the cerebral cortex after a single and fractionated exposure to ionizing radiation in doses of 0.1 – 1.0 Gy. Material and methods. The study was carried out in compliance with the rules of bioethics on 180 white outbred male rats at the age of 4 months. by the beginning of the experiment, exposed to a single or fractionated exposure to γ-quanta of 60Co in total doses of 0.1; 0.2; 0.5 and 1.0 Gy. Neuromorphological and histochemical methods were used to assess morphometric and tinctorial parameters of nerve cells, as well as changes in the content of protein and nucleic acids in neurons in the early and late periods of the post-radiation period. Using one-way analysis of variance, a comparative assessment of neuromorphological indicators under various modes of radiation exposure is given. Results: In the control and irradiated animals throughout their life, undulating changes in the indicators of the state of the neurons of the brain occur with a gradual decrease by the end of the experiment. Despite a number of features of the dynamics of neuromorphological parameters, these irradiation regimes do not cause functionally significant changes in the neurons of the cortex. However, in some periods of the post-radiation period, the changes under the studied irradiation regimes were multidirectional and did not always correspond to age control. Significant differences in the response of neurons to these modes of radiation exposure in the sensory and motor areas of the cerebral cortex have not been established. Conclusion: No functionally significant radiation-induced changes in neurons were found either with single or fractionated irradiation. At the same time, different modes of irradiation in general caused the same type of changes in neurons. However, in some periods of observation, changes in neuromorphological parameters under the studied irradiation regimes were not unidirectional and differed from age control, which indicates a possible risk of disturbances in the functioning of the nervous system against the background of other harmful and dangerous factors.

Implementation of a Fuel Cell System Model Into Building Energy Simulation Software IDA-ICE

2006 ◽  
Vol 4 (4) ◽  
pp. 511-515 ◽  
Author(s):  
Teemu Vesanen ◽  
Krzysztof Klobut ◽  
Jari Shemeikka
Keyword(s):  
Fuel Cell ◽  
Cell Model ◽  
Building Energy ◽  
Cell System ◽  
System Model ◽  
System Level ◽  
Fuel Cell System ◽  
Cell Systems ◽  
Level Model ◽  
System Level Model

Due to constantly increasing electricity consumption, networks are becoming overloaded and unstable. Decentralization of power generation using small-scale local cogeneration plants becomes an interesting option to improve economy and energy reliability of buildings in terms of both electricity and heat. It is expected that stationary applications in buildings will be one of the most important fields for fuel cell systems. In northern countries, like Finland, efficient utilization of heat from fuel cells is feasible. Even though the development of some fuel cell systems has already progressed to a field trial stage, relatively little is known about the interaction of fuel cells with building energy systems during a dynamic operation. This issue could be addressed using simulation techniques, but there has been a lack of adequate simulation models. International cooperation under IEA/ECBCS/Annex 42 aims at filling this gap, and the study presented in this paper is part of this effort. Our objective was to provide the means for studying the interaction between a building and a fuel cell system by incorporating a realistic fuel cell model into a building energy simulation. A two-part model for a solid-oxide fuel cell system has been developed. One part is a simplified model of the fuel cell itself. The other part is a system level model, in which a control volume boundary is assumed around a fuel cell power module and the interior of it is regarded as a “black box.” The system level model has been developed based on a specification defined within Annex 42. The cell model (programed in a spreadsheet) provides a link between inputs and outputs of the black box in the system model. This approach allows easy modifications whenever needed. The system level model has been incorporated into the building simulation tool IDA-ICE (Indoor Climate and Energy) using the neutral model format language. The first phase of model implementation has been completed. In the next phase, model validation will continue. The final goal is to create a comprehensive but flexible model, which could serve as a reliable tool to simulate the operation of different fuel cell systems in different buildings.

Response to Bieko re: Risk of Radiation-Induced Cataracts: Investigation of Radiation Exposure to the Eye Lens During Endourological Procedures

2018 ◽  
Vol 32 (10) ◽  
pp. 905-906
Author(s):  
Florian Distler ◽  
Josefin Hartmann ◽  
Sascha Pahernik ◽  
Michael Wucherer
Keyword(s):  
Radiation Exposure ◽  
Eye Lens ◽  
Radiation Induced

Role of thrombocytopenia in radiation-induced mortality and review of therapeutic approaches targeting platelet regeneration after radiation exposure

2015 ◽  
Vol 5 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Andrea L. DiCarlo ◽  
Joseph M. Kaminski ◽  
Richard J. Hatchett ◽  
Bert W. Maidment
Keyword(s):  
Radiation Exposure ◽  
Therapeutic Approaches ◽  
Radiation Induced

PEMFC Transient Response Characteristics Analysis in Case of Temperature Sensor Failure

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1353
Author(s):  
Jaeyoung Han ◽  
Sangseok Yu ◽  
Jinwon Yun
Keyword(s):  
Fuel Cell ◽  
Temperature Sensor ◽  
Cell Model ◽  
Transient Behavior ◽  
Cell System ◽  
Polymer Electrolyte Fuel Cell ◽  
System Level ◽  
Sensor Fault ◽  
Fuel Cell System ◽  
Free System

In this study, transient responses of a polymer electrolyte fuel cell system were performed to understand the effect of sensor fault signal on the temperature sensor of the stack and the coolant inlet. We designed a system-level fuel cell model including a thermal management system, and a controller to analyze the dynamic behavior of fuel cell system applied with variable sensor fault scenarios such as stuck, offset, and scaling. Under drastic load variations, transient behavior is affected by fault signals of the sensor. Especially, the net power of the faulty system is 45.9 kW. On the other hand, the net power of the fault free system is 46.1 kW. Therefore, the net power of a faulty system is about 0.2 kW lower than that of a fault-free system. This analysis can help in understanding the transient behavior of fuel cell systems at the system level under fault situations and provide a proper failure avoidance control strategy for the fuel cell system.

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