The Effect of Specimen Thickness on Rate of Artificial Aging

1932 ◽  
Vol 5 (4) ◽  
pp. 698-704

Abstract From time to time the question of the effect of thickness on the rate of deterioration of rubber samples subjected to accelerated aging tests, particularly the oxygen-bomb test, is raised. Apparently little experimental work has been done, and no satisfactory answer has yet been given. According to the well-known laws of mass action, the rate of deterioration should slow up with increasing thickness of rubber, and one might expect thin articles to deteriorate further, in a given bomb-aging period, than similar articles of heavier gage. Nevertheless, it is tacitly assumed that variations in thickness have practically no effect—and for small variations this assumption is reasonable considering the oxygen concentration used; or possibly no assumption is made, and the aging tests are just performed mechanically without regard for theoretical considerations and possibilities. The fact that the oxygen-bomb is used largely for comparing the aging quality of similar articles, usually of comparable gage, has doubtless tended to keep the question of the influence of thickness dormant. Again, in the testing of laboratory compounds, most laboratories have standardized on a uniform thickness of cured slabs (0.075″), so that the question of thickness in this type of work does not come into the picture. Occasionally, however, it may be desirable to compare the bomb-aging behavior of articles of quite different types, and when in such cases there is a large difference in thickness, the validity of the comparison may be called in question.

2000 ◽  
Vol 41 (7) ◽  
pp. 197-202 ◽  
Author(s):  
F. Zanelli ◽  
B. Compagnon ◽  
J. C. Joret ◽  
M. R. de Roubin

The utilization of the ChemScan® RDI was tested for different types of water concentrates. Concentrates were prepared by cartridge filtration or flocculation, and analysed either without purification, or after Immunomagnetic separation (IMS) or flotation on percoll-sucrose gradients. Theenumeration of the oocysts was subsequently performed using the ChemScan® RDI Cryptosporidium application. Enumeration by direct microscopic observation of the entire surface of the membrane was carried out as a control, and recoveries were calculated as a ratio between the ChemScan® RDI result and the result obtained with direct microscopic enumeration. The Chemscan enumeration technique proved reliable, with recoveries yielding close to 100% in most cases (average 125%, range from 86 to 467%) for all the concentration/purification techniques tested. The quality of the antibodies was shown to be critical, with antibodies from some suppliers yielding recoveries a low as 10% in some cases. This difficulty could, however, be overcome by the utilization of the antibody provided by Chemunex. These data conclusively prove that laser scanning cytometry, which greatly facilitates the microscopic enumeration of Cryptosporidium oocysts from water samples and decreases the time of observation by four to six times, can be successfully applied to water concentrates prepared from a variety of concentration/purification techniques.


2019 ◽  
Vol 11 (17) ◽  
pp. 4716 ◽  
Author(s):  
Katarzyna Kozicka ◽  
Sebastian Kot ◽  
I Gede Riana

Managing a tourism supply chain is predominantly focused on managing a tourism-specific product that can be perceived as all kinds of goods and services utilized by tourists during their trips. The predominant goal of this article is to empirically identify the level of engagement of entities operating in the tourism-oriented branch of industry concerning the satisfaction of end-customers with the offered tourism-related services and products. Within the scope of this study, the statistical relevance of elements of active cooperation within a tourism-specific supply chain was analyzed. Empirical examinations covered the assessment of the cooperation within the framework of the tourism-oriented supply chain and its impact on consumer satisfaction. A research questionnaire was utilized to meet examination-specific goals. Theoretical considerations and the analysis of branches of industry in relation to the available statistical data showed that tourist-oriented supply chain covers various entities, the engagement of which may have a factual impact on the efficiency of managing the entire chain, as well as on the overall client satisfaction, improving tourism sustainability. The obtained results clearly showed that the examined entities considered the analyzed cooperation aspects to be very important with regard to the supply chain management. Said aspects included the total length of cooperation within the framework of a particular supply chain, which, according to the examined entities, directly translated into the quality of cooperation—to either significant or very significant extent, as well as making it much easier to solve certain problems that were strictly connected with the provision of tourism-oriented services. Yet another aspect of cooperation that was touched upon was the transfer of the so-called know-how between the entities engaged in a given supply chain. As proven by the examination, 70% of the surveyed entities claimed that it was of significant or very significant importance. The last analyzed aspect of cooperation were relations between the supply chain-specific partners and their impact on the satisfaction of end customers. According to over half of the sample (61.54%), decent relations between supply chain participants affected the satisfaction of end customers to a notable extent.


Dermatology ◽  
2021 ◽  
pp. 1-10
Author(s):  
Yaron Har-Shai ◽  
Lior Har-Shai ◽  
Viktor A. Zouboulis ◽  
Christos C. Zouboulis

<b><i>Background:</i></b> Auricular keloids belong to the most perplexing medical conditions, which have significant psychosocial impact on the patient’s body image and quality of life. <b><i>Summary:</i></b> The article is purposed to provide dermatologists and plastic surgeons with the best proven practice using intralesional cryosurgery for the treatment of the different auricular keloid types in order to obtain superior clinical results by minimizing the probability of recurrence. In the past 20 years, the authors have developed novel procedures in order to increase the effectiveness of intralesional cryosurgery on auricular keloids, including hydrodissection, warm gauze technique, and excision of dangling skin. Long-lasting clinical results with a low recurrence rate and a satisfactory aesthetic outcome are achieved with no deformation of the ear framework.


2021 ◽  
pp. 1-21
Author(s):  
Davide Vittori

Abstract Scholars have long debated whether populism harms or improves the quality of democracy. This article contributes to this debate by focusing on the impact of populist parties in government. In particular, it inquires: (1) whether populists in government are more likely than non-populists to negatively affect the quality of democracies; (2) whether the role of populists in government matters; and (3) which type of populism is expected to negatively affect the quality of liberal-democratic regimes. The results find strong evidence that the role of populists in government affects several qualities of democracy. While robust, the findings related to (2) are less clear-cut than those pertaining to (1). Finally, regardless of their role in government, different types of populism have different impacts on the qualities of democracy. The results show that exclusionary populist parties in government tend to have more of a negative impact than other forms of populism.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Donato Lacedonia ◽  
Giulia Scioscia ◽  
Piera Soccio ◽  
Massimo Conese ◽  
Lucia Catucci ◽  
...  

Abstract Background Idiopathic Pulmonary Fibrosis (IPF) is a degenerative interstitial lung disease with both a poor prognosis and quality of life once the diagnosis is made. In the last decade many features of the disease have been investigated to better understand the pathological steps that lead to the onset of the disease and, moreover, different types of biomarkers have been tested to find valid diagnostic, prognostic and therapy response predictive ones. In the complexity of IPF, microRNA (miRNAs) biomarker investigation seems to be promising. Methods We analysed the expression of five exosomal miRNAs supposed to have a role in the pathogenesis of the disease from serum of a group of IPF patients (n = 61) and we compared it with the expression of the same miRNAs in a group of healthy controls (n = 15). Results In the current study what emerged is let-7d down-regulation and, unexpectedly, miR-16 significant down-regulation. Moreover, through a cross-sectional analysis, a clustering of the expression of miR-16, miR-21 and miR-26a was found. Conclusions These findings could help the individuation of previously unknown key players in the pathophysiology of IPF and, most interestingly, more specific targets for the development of effective medications.


Coatings ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 354
Author(s):  
Tim Tofan ◽  
Rimantas Stonkus ◽  
Raimondas Jasevičius

The aim of this research is to investigate related effect of dyeability to linen textiles related to different printing parameters. The study investigated the change in color characteristics when printing on linen fabrics with an inkjet MIMAKI Tx400-1800D printer with pigmented TP 250 inks. The dependence of color reproduction on linen fabrics on the number of print head passes, number of ink layers to be coated, linen fabric density, and different types of linen fabric was investigated. All this affects the quality of print and its mechanical properties. The change in color characteristics on different types of linen fabrics was determined experimentally. We determine at which print settings the most accurate color reproduction can be achieved on different linen fabrics. The difference between the highest and the lowest possible number of head passages was investigated. The possibilities of reproducing different linen fabric colors were determined.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Mirjam Pot ◽  
Nathalie Kieusseyan ◽  
Barbara Prainsack

AbstractThe application of machine learning (ML) technologies in medicine generally but also in radiology more specifically is hoped to improve clinical processes and the provision of healthcare. A central motivation in this regard is to advance patient treatment by reducing human error and increasing the accuracy of prognosis, diagnosis and therapy decisions. There is, however, also increasing awareness about bias in ML technologies and its potentially harmful consequences. Biases refer to systematic distortions of datasets, algorithms, or human decision making. These systematic distortions are understood to have negative effects on the quality of an outcome in terms of accuracy, fairness, or transparency. But biases are not only a technical problem that requires a technical solution. Because they often also have a social dimension, the ‘distorted’ outcomes they yield often have implications for equity. This paper assesses different types of biases that can emerge within applications of ML in radiology, and discusses in what cases such biases are problematic. Drawing upon theories of equity in healthcare, we argue that while some biases are harmful and should be acted upon, others might be unproblematic and even desirable—exactly because they can contribute to overcome inequities.


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