Dosimetric evaluation of methyl red radiochromic film for radiation processing

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Awad AL Zahrany ◽  
Khalid Rabaeh ◽  
Molham Eyadeh ◽  
Ahmed Basfar
Keyword(s):  
Gamma Ray ◽  
Dose Range ◽  
Absorbed Dose ◽  
Radiochromic Film ◽  
High Dose ◽  
Methyl Red ◽  
Radiation Processing ◽  
Content Type ◽  
The Stability ◽  
The Impact

Purpose The purpose of this paper is to present a radiochromic film dosimeter containing polyvinyl alcohol (PVA) matrix and various concentrations of methyl red (MR) dye for high dose measurements. Design/methodology/approach The MR-PVA films were exposed to irradiation up to 60 kGy using 60Co source of gamma ray. The ultraviolet and visible regions (UV/VIS) spectrophotometry were used to examine the optical density of pre-and post-irradiated dosimeters at 424 nm. Findings The dose sensitivity of MR-PVA films increases significantly with increasing MR dye concentrations in the dose range of 5 to 60 kGy. The impact of relative humidity, irradiation temperature, dose rate and the stability of the films has been analyzed. The overall uncertainty of the MR-PVA film dosimeter is 6.12% (Double Standard-deviation, 95% confidence level). Practical implications It was found that the MR-PVA films may be used as high dose dosimeter with an acceptable overall uncertainty in routine industrial radiation processing. Originality/value The color bleaching of irradiated MR-PVA films in terms of specific absorbance curves increases significantly with increasing absorbed dose up to 60 kGy.

Development of two dosimetry systems based on basic violet dye for possible use as radiation dosimeters

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nehad Magdy ◽  
Sameh Gafar
Keyword(s):  
Gamma Ray ◽  
Raw Materials ◽  
Absorbed Dose ◽  
Chemical Yield ◽  
Radiation Sensitivity ◽  
Vital Role ◽  
Radiation Chemical ◽  
Content Type ◽  
Before And After

Purpose The purpose of this research paper is to study a comparison between two dosimetry systems, both of them based on basic violet dye (BV). Design/methodology/approach The first system depends on (BV) (incorporating polyvinyl alcohol) as a thin-film dosimeter. The second system also relies on (BV) as a solution dosimeter, which is more sensitive to gamma rays. The two prepared film/solutions have a considerable signal that decreases upon irradiation and the strength of the signal decreases with increasing radiation dose. Findings The gamma ray absorbed dose for these dosimeters was found to be up to 35 kGy for films and 1 kGy for the liquid phase. All dosimetric characteristics as radiation chemical yield, additive substance, dose-response function, radiation sensitivity, also before and after-irradiation stability under various conditions were considered. Practical implications It is expected the vital role of gamma radiation on this dye in its two forms or two media. This reveals their wide applications in the field of gamma irradiation processing. Originality/value These two dosimetry systems which depend upon the same dye are safe to handle, inexpensive, available raw materials and can be applied in various dosimetry applications as mentioned above.

scholarly journals In VivoTransmission of an IncA/C Plasmid in Escherichia coli Depends on Tetracycline Concentration, and Acquisition of the Plasmid Results in a Variable Cost of Fitness

2015 ◽  
Vol 81 (10) ◽  
pp. 3561-3570 ◽  
Author(s):  
Timothy J. Johnson ◽  
Randall S. Singer ◽  
Richard E. Isaacson ◽  
Jessica L. Danzeisen ◽  
Kevin Lang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
High Dose ◽  
Broad Host Range ◽  
Antibiotic Administration ◽  
Dose Administration ◽  
Content Type ◽  
E Coli ◽  
The Impact ◽  
Selection Of

ABSTRACTIncA/C plasmids are broad-host-range plasmids enabling multidrug resistance that have emerged worldwide among bacterial pathogens of humans and animals. Although antibiotic usage is suspected to be a driving force in the emergence of such strains, few studies have examined the impact of different types of antibiotic administration on the selection of plasmid-containing multidrug resistant isolates. In this study, chlortetracycline treatment at different concentrations in pig feed was examined for its impact on selection and dissemination of an IncA/C plasmid introduced orally via a commensalEscherichia colihost. Continuous low-dose administration of chlortetracycline at 50 g per ton had no observable impact on the proportions of IncA/C plasmid-containingE. colifrom pig feces over the course of 35 days. In contrast, high-dose administration of chlortetracycline at 350 g per ton significantly increased IncA/C plasmid-containingE. coliin pig feces (P< 0.001) and increased movement of the IncA/C plasmid to other indigenousE. colihosts. There was no evidence of conjugal transfer of the IncA/C plasmid to bacterial species other thanE. coli.In vitrocompetition assays demonstrated that bacterial host background substantially impacted the cost of IncA/C plasmid carriage inE. coliandSalmonella.In vitrotransfer and selection experiments demonstrated that tetracycline at 32 μg/ml was necessary to enhance IncA/C plasmid conjugative transfer, while subinhibitory concentrations of tetracyclinein vitrostrongly selected for IncA/C plasmid-containingE. coli. Together, these experiments improve our knowledge on the impact of differing concentrations of tetracycline on the selection of IncA/C-type plasmids.

Consumer responses to the failure of self-service banking technology: moderating role of failure stability

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nedra Bahri Ammari ◽  
Abir Hsouna ◽  
Mounia Benabdallah ◽  
Anish Yousaf ◽  
Abhishek Mishra
Keyword(s):  
Word Of Mouth ◽  
Positive Impact ◽  
Negative Word ◽  
The Self ◽  
Content Type ◽  
Consumer Dissatisfaction ◽  
Self Service ◽  
The Stability ◽  
Self Service Technology ◽  
The Impact

PurposeThe purpose of this study is to investigate the impact of dissatisfaction and anger, driven by the failure of the self-service technology of banks, on customers' post-purchase behavioural reactions, such as complaints, negative word-of-mouth (NWOM) and supplier change. The stability of the failure is proposed to moderate these relationships.Design/methodology/approachThe proposed research model was tested through data collected from an online survey of a Tunisian sample of 300 respondents, using the scenario method.FindingsThe study validates the positive impact of dissatisfaction on anger and negative word-of-mouth, as well as that of anger on complaint behaviour and negative word-of-mouth. The relation between dissatisfaction and negative word-of-mouth is mediated by anger. When the failure is stable, dissatisfied users of the self-service technology seek to enhance their negative word-of-mouth and supplier change. The results also show that the stability of the failure enhances the effect of anger on complaint behaviour.Practical implicationsBanks should invest efforts to accelerate the recovery of services to reduce consumer dissatisfaction and anger and prevent adverse behavioural outcomes. Further, they need to ensure that failures are not repeated, as failure stability activates some otherwise non-significant behavioural outcomes, like supplier change.Originality/valuePrevious works have focused on the impact of dissatisfaction and negative emotions for interpersonal services, but very few works have come to associate dissatisfaction, anger, complaint, negative word-of-mouth and supplier change in an integrative framework for an self-service technology failure.

Radiation induced degradation of murexide dye in two media for possible use in dosimetric applications

2019 ◽  
Vol 48 (6) ◽  
pp. 540-546 ◽  
Author(s):  
Sameh Mohamed Gafar ◽  
Nehad Magdy Abdel-Kader
Keyword(s):  
Gamma Rays ◽  
Gamma Ray ◽  
Absorbed Dose ◽  
Chemical Yield ◽  
Radiation Sensitivity ◽  
Industrial Applications ◽  
Food Irradiation ◽  
Radiation Chemical ◽  
Content Type ◽  
Wide Range

Purpose The purpose of this paper is to study the effect of gamma-rays on murexide (Mx) dye and its possible use as radiation dosimeters in two different dosimetry systems. The first system depends on the Mx dye as a liquid dosimeter. The second dosimetry system depends also on the same dye but as in a gel form, which is more sensitive to gamma-rays. Design/methodology/approach The prepared Mx (solutions/gels) have a considerable two peaks at 324 and 521 nm that upon irradiation, the intensity of these peaks decreases with the increasing radiation dose. Findings The gamma-ray absorbed dose for these dosimeters was found to be up to 2 kGy for the solution samples and 40 Gy for the gels. Radiation chemical yield, dose response function, radiation sensitivity and before and after-irradiation stability under various conditions were discussed and studied. Practical implications It is expected that the radiolysis of the Mx dye can be used as radiation dosimeters in two different dosimetry systems; liquid and gel dosimeters. This can be applied in a wide range of gamma radiation practical industrial applications in water treatment, food irradiation dosimeters, radiotherapy and fresh food irradiation and seed production. Originality/value Both of the prepared Mx dyes, either as solutions or gel samples, can be facilely prepared from commercially, cheap, safe, available chemicals and suitable for useful applied Mx solutions and gels radiation dosimeters.

Knowledge diversity and firm performance: an ecological view

2016 ◽  
Vol 20 (4) ◽  
pp. 671-686 ◽  
Author(s):  
Deng-Neng Chen ◽  
Ting-Peng Liang
Keyword(s):  
Knowledge Management ◽  
Firm Performance ◽  
Organizational Performance ◽  
Company Performance ◽  
Content Type ◽  
Knowledge Diversity ◽  
Ecological View ◽  
New Perspective ◽  
The Stability ◽  
The Impact

Purpose Knowledge has been considered a crucial organizational asset for gaining competitive advantages. It is critical for a firm to maintain a knowledge composition that is productive. This study aims to examine the applicability of the diversity–stability principle in ecology to knowledge management and further investigate the impact of knowledge diversity on firm performance. Design/methodology/approach A theoretical framework for knowledge diversity and firm performance is proposed; a questionnaire survey was conducted to evaluate the research framework. Fifty-eight valid responses from experts were collected to measure knowledge strength and diversity of 20 enterprises in four industries, and financial indexes of the 20 enterprises from 2008 to 2012 were collected to analyze the research model. Findings The results show that higher information technology (IT) capabilities in a firm lead to higher levels of knowledge strength and diversity. The strength and diversity of knowledge in a company can improve average company performance and reduce performance variations. Research limitations/implications This paper presents a new perspective that applies the ecological concept of diversity to examine the value of knowledge in organizations. The findings expand our understanding of the role of IT and knowledge in organizational performance. A limitation is that the sample size is relatively small, which may limit the generalizability of the findings. Practical implications CEOs and chief knowledge officers can apply the findings herein to assess their organizational knowledge profiles and maintain a healthy knowledge ecology in strategic planning. They should be aware that both knowledge strength and knowledge diversity are crucial to the stability of firm performance. Originality/value The ecological view of knowledge management stresses the importance of maintaining a healthy intensity and diversity of knowledge at the macro level and indicates a new direction for knowledge management.

Irradiation test and hardness design for mobile rescue robot in nuclear environment

2019 ◽  
Vol 46 (6) ◽  
pp. 851-862
Author(s):  
Wenrui Gao ◽  
Weidong Wang ◽  
Hongbiao Zhu ◽  
Shunping Zhao ◽  
Guofu Huang ◽  
...  
Keyword(s):  
Field Experiment ◽  
Gamma Ray ◽  
Radiation Environment ◽  
High Dose ◽  
Distance Protection ◽  
Efficient Operation ◽  
Content Type ◽  
Mobility Performance ◽  
Irradiation Test ◽  
Operational Practices

Purpose The paper aims to improve the radiation-proof capability of the self-designed mobile robot with a 7-DOF manipulator, enabling the long-playing inspection and intervention under high-dose radiation environment. In this context, gamma-ray irradiation test for electronic components and specific hardness design have also been specifically presented and discussed. Design/methodology/approach The study’s hardness design mainly focuses on shielding protection, distance protection and time protection. Irradiation test is first carried out to investigate irradiation resistance of each electronic module. Then, modular deployment and shielding calculation are completed for the point-type nuclear accidents, respectively, to achieve a robust anti-radiation design scheme. Finally, the field experiment is conducted to validate system effectiveness and good mobility, and operational practices are acquired for the realization of time protection. Findings Coupled with modular redeployment and shielding design, irradiation results illustrate the effectiveness of robotic anti-radiation design. Meanwhile, experiences and reformed measures from the field exercise implement efficient operation and radiological time protection. Research limitations/implications Considering the huge risks of high-dose source exposure, the radiation-resistance of the overall system cannot be verified in the field experiment. Fortunately, irradiation test and modular shielding calculation are conducted as a minimal validation. Practical implications The proposed anti-radiation design methods and the irradiated results can be applied to many other nuclear vehicles and manipulators for the feasible multi-layer protection and excellent mobility. Originality/value A nuclear intervention robot with specific hardness design is presented in detail in this paper. Enlightened by the idea of shielding and distance protection, a large number of electronic modules with multiple types and structures are treated and compared in irradiation experiments, while modular redeployment and retrofitting are completed to reduce irradiated damages. To achieve the effect of time protection, mobility performance and operational practices are discussed and validated in the field experiment based on the mobile system.

scholarly journals Temperature Control ofpsaAExpression by PsaE and PsaF inYersinia pestis

2019 ◽  
Vol 201 (16) ◽  
Author(s):  
Joshua D. Quinn ◽  
Eric H. Weening ◽  
Taryn A. Miner ◽  
Virginia L. Miller
Keyword(s):  
High Temperature ◽  
Posttranscriptional Regulation ◽  
Yersinia Pseudotuberculosis ◽  
Bacterial Pathogen ◽  
Mammalian Host ◽  
Bubonic Plague ◽  
Content Type ◽  
Environmental Signals ◽  
The Stability ◽  
The Impact

ABSTRACTPsaA, the subunit of the fimbria originally referred to as the “pH 6 antigen,” is required for full virulence ofYersinia pestisduring bubonic plague. The expression ofpsaAis dependent upon specific environmental signals, and while the signals (high temperature and acidic pH) are defined, the mechanisms underlying this regulation remain unclear. In the closely related speciesYersinia pseudotuberculosis,psaAtranscription requires two regulatory genes,psaEandpsaF, and it is speculated that posttranscriptional regulation of PsaE and/or PsaF contributes to the regulation ofpsaAtranscription. Few studies have examined the regulation ofpsaAexpression inY. pestis, and prior to this work, the roles ofpsaEandpsaFinY. pestishad not been defined. The data presented here show that bothpsaEandpsaFare required forpsaAtranscription inY. pestisand that the impact of temperature and pH is mediated through discrete posttranscriptional effects on PsaE and PsaF. By generating antibodies that recognize endogenous PsaE and PsaF, we determined that the levels of both proteins are impacted by temperature and pH. High temperature is required forpsaEandpsaFtranslation via discrete mechanisms mediated by the mRNA 5′ untranslated region (UTR) upstream of each gene. Additionally, levels of PsaE and PsaF are impacted by pH. We show that PsaF enhances the stability of PsaE, and thus, both PsaE and PsaF are required forpsaAtranscription. Our data indicate that the environmental signals (temperature and pH) impact the expression ofpsaAby affecting the translation ofpsaEandpsaFand the stability of PsaE and PsaF.IMPORTANCEY. pestisis a Gram-negative bacterial pathogen that causes bubonic plague. As a vector-borne pathogen,Y. pestisfluctuates between an arthropod vector (flea) and mammalian host. As such,Y. pestismust recognize environmental signals encountered within each host environment and respond by appropriately regulating gene expression. PsaA is a keyY. pestismammalian virulence determinant that forms fimbriae. Our work provides evidence thatY. pestisutilizes multiple posttranscriptional mechanisms to regulate the levels of two PsaA regulatory proteins in response to both temperature and pH. This study offers insight into mechanisms that bacteria utilize to sense environmental cues and regulate the expression of determinants required for mammalian disease.

The impact of long-term riskless asset on ensuring liquidity and preventing banking fragility

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mahmoud Shahin
Keyword(s):  
Risk Sharing ◽  
Content Type ◽  
Asset Portfolio ◽  
Illiquid Asset ◽  
The Stability ◽  
Gain Loss ◽  
Riskless Asset ◽  
The Impact ◽  
Liquidation Cost

PurposeThrough portfolio diversification, the author identifies the risk sharing deposit contract in a three-period model that maximizes the ex ante expected utility of depositors.Design/methodology/approachIn this paper, the author extends the study by Allen and Gale (1998) by adding a long-term riskless investment opportunity to the original portfolio of a short-term liquid asset and a long-term risky illiquid asset.FindingsUnlike Allen and Gale, there are no information-based bank runs in equilibrium. In addition, the model can improve consumers' welfare over the Allen and Gale model. The author also shows that the bank will choose to liquidate the cheaper investments, in terms of the gain-loss ratios for the two types of existing long-term assets, when there is liquidity shortage in some cases. Such a policy reduces the liquidation cost and enables the bank to meet the outstanding liability to depositors without large liquidation losses.Originality/valueThe author believe that the reader would be interested in this article because it is relevant to real world where depositors rush to withdraw their deposits from a bank if there is negative information about future prospect of the bank asset portfolio and bank investment. Economists and financial analysts need to determine the suitable mechanism to improve the stability of the bank and the depositor welfare.

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