scholarly journals Investigating artifacts associated with β-particle interactions in charge-coupled devices

2018 ◽  
Vol 48 ◽  
pp. 1860117
Author(s):  
Rosie Newton ◽  
Mike J. Scott ◽  
Malcolm J. Joyce

Charge-coupled devices (CCDs) show potential for detecting charged particles and ionizing radiation. In particular, the clusters in the pixel images produced can be distinctive for [Formula: see text] and [Formula: see text] radiation, with [Formula: see text] particles causing symmetrical clusters or vertical tracks, and [Formula: see text] particles causing long, curved tracks. This distinction may be exploited by means of a handheld, portable device for in-situ detection, and identification of radioactive contamination. [Formula: see text]-particle track interactions in CCDs have been investigated. Simulative results using CASINO (Monte Carlo Simulation of Electron Trajectory in Solids) attempt to predict the size of [Formula: see text]-particle pixel clusters, using 512 keV and 310 keV electrons to represent [Formula: see text]Cs and [Formula: see text]Co, respectively. The number of pixels that higher-energy electrons traversed peaked at two, while lower-energy electrons had a smaller peak of 2.5 pixels, with a higher proportion of large cluster sizes. This finding is consistent with the higher scattering cross-section for lower-energy [Formula: see text] particles. By contrast, experimental data show a peak at one pixel for both sources, owing to the addition of smaller [Formula: see text] clusters. The [Formula: see text]Co source shows a higher proportion of large cluster sizes than the [Formula: see text]Cs, as was also seen in the simulation; however, the difference was small, as these sources are similar in energy. Simulative and experimental data will be used to process the CCD images further, with the objective of distinguishing between [Formula: see text] and [Formula: see text] radiation. Investigations have also been carried out using a [Formula: see text]Po [Formula: see text] particle source. Horizontal streaks were seen in the images produced, with an average length of 14 pixels. Further research will be performed using an accelerator to obtain different [Formula: see text]-particle energies.

2020 ◽  
Vol 239 ◽  
pp. 06006
Author(s):  
Shin-ichiro MEIGO ◽  
Hiroki MATSUDA ◽  
Yosuke IWAMOTO ◽  
Makoto YOSHIDA ◽  
Shoichi HASEGAWA ◽  
...  

For damage estimation of structural material in the accelerator facility, displacement per atom (DPA) is widely employed as an index of the damage calculated based on the displacement cross section obtained with the calculation model. Although the DPA is employed as the standard, the experimental data of displacement cross section are scarce for a proton in the energy region above 20 MeV. Among the calculation models, the difference exists about 8 times so that experimental data of the displacement cross section is crucial to validate the model. To obtain the displacement cross section, we conducted the experiment in J-PARC. As a preliminary result, the displacement cross section of copper was successfully obtained for 3-GeV proton. The present results showed that the widely utilized the Norgertt-Robinson-Torrens (NRT) model overestimates the cross section as suggested by the previous experiment for protons with lower energy.


2020 ◽  
Vol 225 ◽  
pp. 01010
Author(s):  
Rosie Newton ◽  
Mike J. Scott ◽  
Malcolm J. Joyce

Charge coupled devices (CCDs) have been shown to have potential for detecting charged particles and other forms of ionising radiation. In particular, the clusters in the pixel images produced are distinctive for α and β radiations, with α particles causing large, symmetrical clusters or long, vertical tracks often referred to as blooming, and β particles causing long, curved tracks. The size and shape of these tracks are also related to the energy of the incident radiation, giving the potential for spectroscopy of these types of radiation. This could be used, for example, to realise a hand-held, portable device for in-situ detection and identification of radioactive contamination. Images have been taken of exposures to a 210Po α-particle source using Sony ICX825AL interline transfer CCDs, covered with a thin, aluminised Mylar film to prevent inadvertent exposure to light. Both vertical streaks and round clusters have been observed in each of the three CCDs used. Increased levels of noise have been seen after several hours of exposure to the 210Po source, found to be caused by damage from α radiation. Three methods have been investigated to reduce this noise: 1) Annealing at 100°C for 24 hours repairs a significant proportion of the damage caused by the α radiation, though the effectiveness is reduced with each subsequent exposure and annealing cycle; 2) Cooling is performed during exposures by using a heat pipe to move heat away from the back of the CCD and a fan to cool the heat pipe and electronics associated with the CCD.This reduces the dark current during CCDmeasurements, and the method of cooling used allows thedevice to retain its small, hand-held size; 3) Anyremaining noise can be removed later using imageprocessing. These techniques are combined to extend thelifetime of the device. The rate of damage from the 210Posource is similar whether the device is cooled or not,however the noise evident in the images produced whencooled is significantly less, allowing the CCD to be usedfor a longer time between annealing operations.


2021 ◽  
pp. 089719002110212
Author(s):  
Brandy Williams ◽  
Justin Muklewicz ◽  
Taylor D. Steuber ◽  
April Williams ◽  
Jonathan Edwards

Background: Shifting inpatient antibiotic treatment to outpatient parenteral antimicrobial therapy may minimize treatment for acute bacterial skin and skin structure infections, including cellulitis. The purpose of this evaluation was to compare 30-day hospital readmission or admission due to cellulitis and economic outcomes of inpatient standard-of-care (SoC) management of acute uncomplicated cellulitis to outpatient oritavancin therapy. Methods: This retrospective, observational cohort study was conducted at a 941-bed community teaching hospital. Adult patients 18 years and older treated for acute uncomplicated cellulitis between February 2015 to December 2018 were eligible for inclusion. Information was obtained from hospital and billing department records. Patients were assigned to either inpatient SoC or outpatient oritavancin cohorts for comparison. Results: 1,549 patients were included in the study (1,348 in the inpatient SoC cohort and 201 in the outpatient oritavancin cohort). The average length of stay for patients admitted was 3.6 ± 1.5 days. The primary outcome of 30-day hospital readmission or admission due to cellulitis occurred in 49/1348 (3.6%) patients in the inpatient SoC cohort versus 1/201 (0.5%) in the outpatient oritavancin cohort (p = 0.02). The difference between costs and reimbursement was improved in the outpatient oritavancin group (p < 0.001). Conclusion: Outpatient oritavancin for acute uncomplicated cellulitis was associated with reduction in 30-day hospital readmissions or admissions compared to inpatient SoC. Beneficial economic outcomes for the outpatient oritavancin cohort were observed. Additional studies are required to confirm these findings.


2021 ◽  
Vol 11 (2) ◽  
Author(s):  
Yin Chung Au

AbstractThis paper proposes an extended version of the interventionist account for causal inference in the practical context of biological mechanism research. This paper studies the details of biological mechanism researchers’ practices of assessing the evidential legitimacy of experimental data, arguing why quantity and variety are two important criteria for this assessment. Because of the nature of biological mechanism research, the epistemic values of these two criteria result from the independence both between the causation of data generation and the causation in question and between different interventions, not techniques. The former independence ensures that the interventions in the causation in question are not affected by the causation that is responsible for data generation. The latter independence ensures the reliability of the final mechanisms not only in the empirical but also the formal aspects. This paper first explores how the researchers use quantity to check the effectiveness of interventions, where they at the same time determine the validity of the difference-making revealed by the results of interventions. Then, this paper draws a distinction between experimental interventions and experimental techniques, so that the reliability of mechanisms, as supported by the variety of evidence, can be safely ensured in the probabilistic sense. The latter process is where the researchers establish evidence of the mechanisms connecting the events of interest. By using case studies, this paper proposes to use ‘intervention’ as the fruitful connecting point of literature between evidence and mechanisms.


2004 ◽  
Vol 19 (12) ◽  
pp. 3607-3613 ◽  
Author(s):  
H. Iikawa ◽  
M. Nakao ◽  
K. Izumi

Separation by implemented oxygen (SIMOX)(111) substrates have been formed by oxygen-ion (16O+) implantation into Si(111), showing that a so-called “dose-window” at 16O+-implantation into Si differs from Si(100) to Si(111). In SIMOX(100), an oxygen dose of 4 × 1017/cm2 into Si(100) is widely recognized as the dose-window when the acceleration energy is 180 keV. For the first time, our work shows that an oxygen dose of 5 × 1017/cm2 into Si(111) is the dose-window for the formation of SIMOX(111) substrates when the acceleration energy is 180 keV. The difference between dose-windows is caused by anisotropy of the crystal orientation during growth of the faceted buried SiO2. We also numerically analyzed the data at different oxidation velocities for each facet of the polyhedral SiO2 islands. Numerical analysis results show good agreement with the experimental data.


2011 ◽  
Vol 321 ◽  
pp. 192-195
Author(s):  
Qing Bin Yang ◽  
Xiao Yang

In order to analysis the relationship between the strength and elongation and the blended ratio of SPF/Cotton blended yarn, the strength and elongation of SPF /cotton blended yarn with different blended ratio were measured and compared with the simple model. The results indicated that For the SPF/cotton blended yarn, the difference between the experimental data and the model value is remarkable because of the high cohesion of the cotton fibers.


1995 ◽  
Vol 89 (4) ◽  
pp. 405-415 ◽  
Author(s):  
R. L. Sidebotham ◽  
J. H. Baron ◽  
J. Schrager ◽  
J. Spencer ◽  
J. R. Clamp ◽  
...  

1. The content and distribution of carbohydrate was examined in mucus glycopolypeptides from human antral mucosae. 2. The mean amount of carbohydrate per 1000 amino acid residues was found to be similar in glycopolypeptides with A, B or H activity. It was slightly, though significantly, less in glycopolypeptides lacking these determinants, because carbohydrate chains were of a shorter average length than in the A-, B- or H-active preparations. This difference was reflected in the sizes of oligosaccharide—alcohols released from representative glycopolypeptides with alkaline borohydride. 3. Differences between A-, B- or H-active and non-secretor glycopolypeptides in terms of the mean number of carbohydrate chains per 1000 amino acid residues were found to be small, and without significance. 4. The average number of peripheral monosaccharide units per 1000 amino acid residues was greater in A-active than in H-active, and least in non-secretor, glycopolypeptides. This order was reversed for monosaccharide units incorporated into skeletal (core plus backbone) structures. The difference in each case was statistically significant. 5. These findings suggest that the increased risk of peptic ulcer associated with blood group O and non-secretor status is unlikely to be attributable to an inherent deficiency in the protective mucus layer, linked to differences between mucins that are associated with A, B or H activity. Other hypotheses linked to infection with Helicobacter pylori are examined.


2020 ◽  
pp. 5-11
Author(s):  
Vladimir Kurteyev ◽  
◽  
Boris Mozerov ◽  

There is studied the problems experiment modeling under impact of torn vane with turbojet fan case. There are outlined shortcomings of equipment for plane and cylindrical model cases testing. There is indicated the difference between calculation results and experimental data for metals plane models. There are indicated diagram laboratory experiment installation on basic pressurized balloons for testing metals plane models. There are calculated parameters of metals plane model with the point of views criterion modeling.


2021 ◽  
Vol 63 (7) ◽  
pp. 982
Author(s):  
Б. Лю ◽  
В.И. Хвесюк ◽  
А.А. Баринов

In this work, we have formulated and solved the problem of determining the Kapitza conductance across the interface between two solids, taking into account the interface roughness. We use a modified acoustic mismatch model (AMM). The difference from the classic model is that the dispersion properties of acoustic waves are considered. A significant advantage of this model is that the theoretical prediction agrees well with experimental data over a wide temperature range: from 30K to more than 300K. Finally, a theoretical method with the statistical distribution of roughness profiles is used to determine the energy transmission coefficient across the interface.


2021 ◽  
Author(s):  
Ahmad T. Kalaji

This thesis presents a flexible trailing edge mechanism capable of undergoing a change in camber for a wing section. The mechanism takes advantage of a rigid constraint between the ends of two flexible carbon fiber panels, which produces a deflection when there is a difference in length between the two panels. A prototype was designed and built and experimental data was collected for the deformation of the panels for different values of lengths and analyzed to find a function to describe the coefficients which form the polynomials describing the shape for each of the panels, based on the difference in length value. Deflection and deflection angle results were used to develop a controller which will calculate the required change in length based on a deflection or angle and a bottom panel length input.


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