scholarly journals Plutonium dioxide particle imaging using a high-resolution alpha imager for radiation protection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuki Morishita ◽  
Shunsuke Kurosawa ◽  
Akihiro Yamaji ◽  
Masateru Hayashi ◽  
Makoto Sasano ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Spatial Resolution ◽  
Optical Microscope ◽  
Exposure Dose ◽  
Alpha Particles ◽  
Internal Exposure ◽  
Beta Particle ◽  
Nuclear Facilities ◽  
Plutonium Dioxide

AbstractThe internal exposure of workers who inhale plutonium dioxide particles in nuclear facilities is a crucial matter for human protection from radiation. To determine the activity median aerodynamic diameter values at the working sites of nuclear facilities in real time, we developed a high-resolution alpha imager using a ZnS(Ag) scintillator sheet, an optical microscope, and an electron-multiplying charge-coupled device camera. Then, we designed and applied a setup to measure a plutonium dioxide particle and identify the locations of the individual alpha particles in real time. Employing a Gaussian fitting, we evaluated the average spatial resolution of the multiple alpha particles was evaluated to be 16.2 ± 2.2 μmFWHM with a zoom range of 5 ×. Also, the spatial resolution for the plutonium dioxide particle was 302.7 ± 4.6 µmFWHM due to the distance between the plutonium dioxide particle and the ZnS(Ag) scintillator. The influence of beta particles was negligible, and alpha particles were discernible in the alpha–beta particle contamination. The equivalent volume diameter of the plutonium dioxide particle was calculated from the measured count rate. These results indicate that the developed alpha imager is effective in the plutonium dioxide particle measurements at the working sites of nuclear facilities for internal exposure dose evaluation.

scholarly journals Low Energy Beta Emitter Measurement: A Review

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 106
Author(s):  
Hara Kang ◽  
Sujung Min ◽  
Bumkyung Seo ◽  
Changhyun Roh ◽  
Sangbum Hong ◽  
...  
Keyword(s):  
Radiation Detection ◽  
The Body ◽  
Low Energy ◽  
Internal Exposure ◽  
Beta Particle ◽  
Radiation Hazard ◽  
Nuclear Facilities ◽  
Beta Particles ◽  
Beta Emitter ◽  
Plastic Scintillators

The detection and monitoring systems of low energy beta particles are of important concern in nuclear facilities and decommissioning sites. Generally, low-energy beta-rays have been measured in systems such as liquid scintillation counters and gas proportional counters but time is required for pretreatment and sampling, and ultimately it is difficult to obtain a representation of the observables. The risk of external exposure for low energy beta-ray emitting radioisotopes has not been significantly considered due to the low transmittance of the isotopes, whereas radiation protection against internal exposure is necessary because it can cause radiation hazard to into the body through ingestion and inhalation. In this review, research to produce various types of detectors and to measure low-energy beta-rays by using or manufacturing plastic scintillators such as commercial plastic and optic fiber is discussed. Furthermore, the state-of-the-art beta particle detectors using plastic scintillators and other types of beta-ray counters were elucidated with regard to characteristics of low energy beta-ray emitting radioisotopes. Recent rapid advances in organic matter and nanotechnology have brought attention to scintillators combining plastics and nanomaterials for all types of radiation detection. Herein, we provide an in-depth review on low energy beta emitter measurement.

440 EVALUATION OF FOLLICULAR GROWTH AFTER EXOGENOUS STIMULATION IN MICE USING ULTRASOUND BIOMICROSCOPY

2010 ◽  
Vol 22 (1) ◽  
pp. 377
Author(s):  
P. H. A. Campos-Junior ◽  
C. S. Silva ◽  
J. G. V. Grázia ◽  
R. I. T. P. Batista ◽  
V. V. Maffili ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Spatial Resolution ◽  
Maximum Size ◽  
Ultrasound Biomicroscopy ◽  
Follicular Growth ◽  
Small Rodents ◽  
The Moment ◽  
Large Animals ◽  
Follicular Dynamics

Real-time follicular dynamics studies have often been restricted to large animals because of the resolution of ultrasound equipment available. The recent advances in image technology, including significant gains in spatial resolution, allowed these evaluations to be performed in small rodents, which are important models to understand folliculogenesis. The aim of this study was to evaluate exogenous stimulated follicular growth in mice using a high resolution ultrasound. Female mice (n = 15) received a 5 IU i.p. injection of eCG (Vetecor®, Calier) and 48 h later a 5 IU injection of hCG (Novormon®, Schering-Plough), and were mated thereafter. In experiment 1, animals (n = 7) were anesthetized with ketamin/xilazin solution and evaluated at 3, 9, 15, 21, 27, 33, 45, and 51 h after eCG injection. The ovaries were identified with ultrasound biomicroscopy (UBM, Vevo 660®, Visual Sonics, Toronto, ON, Canada) coupled with real-time micro-visualization probe (RMV 707b), and the follicular population was measured, quantified, and classified into small follicles (≤449 μm) and large follicles (≥450 μm). The number of small follicles decreased (P < 0.05) from 30.44 ± 15.91 to 14.79 ± 7.23, and the number of large follicles (≥450 μm) increased from 0.36 ± 0.74 to 4.21 ± 4.25. For both size classes, however, statistical differences only occurred at 45 h after eCG; that is, close to the moment of hCG injection. In experiment 2, animals (n = 8) were evaluated every 2 h beginning 4.5 h after hCG to check for ovulations. The largest follicles achieved a mean maximum size of 596.7 ± 106.0 μm, 5.8 ± 2.3 h after hCG application. In 5 animals, large follicles were observed at 2 distinct moments, 5.0 ± 1.2 h and 10.4 ± 1.0 h after hCG, respectively. Results suggest that the later stages of follicular growth in mice are only achieved a few hours before ovulation, and that ovulations induced by hCG are not synchronized. Financial suport: Fapemig, CBTC São Rafael, CNPq.

Real-time assessment of exposure dose to workers in radiological environments during decommissioning of nuclear facilities

2014 ◽  
Vol 73 ◽  
pp. 441-445 ◽  
Author(s):  
KwanSeong Jeong ◽  
ByungSeon Choi ◽  
JeiKwon Moon ◽  
Dongjun Hyun ◽  
Jonghwan Lee ◽  
...  
Keyword(s):  
Real Time ◽  
Exposure Dose ◽  
Nuclear Facilities ◽  
Time Assessment

Cosmetology treatments on human hair: An SEM study

1996 ◽  
Vol 54 ◽  
pp. 940-941
Author(s):  
D.F. Bowling
Keyword(s):  
High School ◽  
High Resolution ◽  
Human Hair ◽  
Optical Microscope ◽  
Convincing Evidence ◽  
Brightness Contrast ◽  
Sem Study

High school cosmetology students study the methods and effects of various human hair treatments, including permanents, straightening, conditioning, coloring and cutting. Although they are provided with textbook examples of overtreatment and numerous hair disorders and diseases, a view of an individual hair at the high resolution offered by an SEM provides convincing evidence of the hair‘s altered structure. Magnifications up to 2000X provide dramatic differences in perspective. A good quality classroom optical microscope can be very informative at lower resolutions.Students in a cosmetology class are initially split into two groups. One group is taught basic controls on the SEM (focus, magnification, brightness, contrast, specimen X, Y, and Z axis movements). A healthy, untreated piece of hair is initially examined on the SEM The second group cements a piece of their own hair on a stub. The samples are dryed quickly using heat or vacuum while the groups trade places and activities.

New form of Transmission Cross Coefficient for High-Resolution Imaging

1990 ◽  
Vol 48 (1) ◽  
pp. 60-61
Author(s):  
Kazuo Ishizuka
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Transmission Function ◽  
Incident Beam ◽  
Optical Microscope ◽  
Strong Interactions ◽  
Small Range ◽  
Specimen Thickness ◽  
Beam Direction ◽  
Diffracted Waves

It is well known that taking into account spacial and temporal coherency of illumination as well as the wave aberration is important to interpret an image of a high-resolution electron microscope (HREM). This occues, because coherency of incident electrons restricts transmission of image information. Due to its large spherical and chromatic aberrations, the electron microscope requires higher coherency than the optical microscope. On an application of HREM for a strong scattering object, we have to estimate the contribution of the interference between the diffracted waves on an image formation. The contribution of each pair of diffracted waves may be properly represented by the transmission cross coefficients (TCC) between these waves. In this report, we will show an improved form of the TCC including second order derivatives, and compare it with the first order TCC.In the electron microscope the specimen is illuminated by quasi monochromatic electrons having a small range of illumination directions. Thus, the image intensity for each energy and each incident direction should be summed to give an intensity to be observed. However, this is a time consuming process, if the ranges of incident energy and/or illumination direction are large. To avoid this difficulty, we can use the TCC by assuming that a transmission function of the specimen does not depend on the incident beam direction. This is not always true, because dynamical scattering is important owing to strong interactions of electrons with the specimen. However, in the case of HREM, both the specimen thickness and the illumination angle should be small. Therefore we may neglect the dependency of the transmission function on the incident beam direction.

Mapping and Monitoring of the Land Use/Cover Changes in the Wider Area of ltanos, Crete, Using Very High Resolution EO Imagery With Specific Interest in Archaeological Sites

2019 ◽  
Author(s):  
Sawyer Reid stippa ◽  
George Petropoulos ◽  
Leonidas Toulios ◽  
Prashant K. Srivastava
Keyword(s):  
High Resolution ◽  
Spatial Resolution ◽  
Satellite Images ◽  
Archaeological Site ◽  
Digital Photography ◽  
Archaeological Sites ◽  
Large Area ◽  
High Resolution Imagery ◽  
Site Mapping ◽  
Rule Sets

Archaeological site mapping is important for both understanding the history as well as protecting them from excavation during the developmental activities. As archaeological sites generally spread over a large area, use of high spatial resolution remote sensing imagery is becoming increasingly applicable in the world. The main objective of this study was to map the land cover of the Itanos area of Crete and of its changes, with specific focus on the detection of the landscape’s archaeological features. Six satellite images were acquired from the Pleiades and WorldView-2 satellites over a period of 3 years. In addition, digital photography of two known archaeological sites was used for validation. An Object Based Image Analysis (OBIA) classification was subsequently developed using the five acquired satellite images. Two rule-sets were created, one using the standard four bands which both satellites have and another for the two WorldView-2 images their four extra bands included. Validation of the thematic maps produced from the classification scenarios confirmed a difference in accuracy amongst the five images. Comparing the results of a 4-band rule-set versus the 8-band showed a slight increase in classification accuracy using extra bands. The resultant classifications showed a good level of accuracy exceeding 70%. Yet, separating the archaeological sites from the open spaces with little or no vegetation proved challenging. This was mainly due to the high spectral similarity between rocks and the archaeological ruins. The satellite data spatial resolution allowed for the accuracy in defining larger archaeological sites, but still was a difficulty in distinguishing smaller areas of interest. The digital photography data provided a very good 3D representation for the archaeological sites, assisting as well in validating the satellite-derived classification maps. All in all, our study provided further evidence that use of high resolution imagery may allow for archaeological sites to be located, but only where they are of a suitable size archaeological features.

Electrical Probing and Surface Imaging of Deep Sub-Micron Integrated Circuits

1999 ◽  
Author(s):  
Kenneth Krieg ◽  
Richard Qi ◽  
Douglas Thomson ◽  
Greg Bridges
Keyword(s):  
High Resolution ◽  
Integrated Circuits ◽  
Real Time ◽  
High Speed ◽  
Time Signal ◽  
Surface Imaging ◽  
Atomic Force ◽  
Submicron Structures ◽  
High Resolution Images ◽  
Capacitive Loading

Abstract A contact probing system for surface imaging and real-time signal measurement of deep sub-micron integrated circuits is discussed. The probe fits on a standard probe-station and utilizes a conductive atomic force microscope tip to rapidly measure the surface topography and acquire real-time highfrequency signals from features as small as 0.18 micron. The micromachined probe structure minimizes parasitic coupling and the probe achieves a bandwidth greater than 3 GHz, with a capacitive loading of less than 120 fF. High-resolution images of submicron structures and waveforms acquired from high-speed devices are presented.

High Resolution Current Imaging by Direct Magnetic Field Sensing

2003 ◽  
Author(s):  
S.I. Woods ◽  
Nesco M. Lettsome ◽  
A.B. Cawthorne ◽  
L.A. Knauss ◽  
R.H. Koch
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Spatial Resolution ◽  
Great Promise ◽  
Magnetoresistive Sensor ◽  
Magnetic Sensitivity ◽  
Current Lines ◽  
Scanning Squid ◽  
Scanning Fiber ◽  
Ferromagnetic Probe

Abstract Two types of magnetic microscopes have been investigated for use in high resolution current mapping. The scanning fiber/SQUID microscope uses a SQUID sensor coupled to a nanoscale ferromagnetic probe, and the GMR microscope employs a nanoscale giant magnetoresistive sensor. Initial scans demonstrate that these microscopes can resolve current lines less than 10 µm apart with edge resolution of 1 µm. These types of microscopes are compared with the performance of a standard scanning SQUID microscope and with each other with respect to spatial resolution and magnetic sensitivity. Both microscopes show great promise for identifying current defects in die level devices.

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