Nano Scale Creep and the Role of Defects

1996 ◽  
Vol 436 ◽  
Author(s):  
S. A. Syed Asif ◽  
J. B. Pethica

AbstractThe modulating force method in nanoindentation gives a direct measure of contact stiffness, and being insensitive to drift, allows the accurate observation of creep in small indents to be carried out over long time periods. We present results for a range of metals at room temperature. Strain rate indices similar to those for macroscopic creep are found. Reverse creep occurs for step unloading greater than about half the starting load. For electropolished tungsten, we find quite different behaviour before and after the sudden pop-in. Afterwards, creep is as in other metals, but beforehand, it is essentially zero. The slight changes of stiffness observed at the very smallest loads are due to diffusion of adsorbed surface films into the contact zone. Our results show that the dislocations nucleated and multiplied at pop-in provide the mechanism of creep.

Clay Minerals ◽  
1997 ◽  
Vol 32 (1) ◽  
pp. 29-40 ◽  
Author(s):  
K. A. Carrado ◽  
P. Thiyagarajan ◽  
K. Song

AbstractA method has been developed to synthesize organo-hectorite clays directly from a Mg-silicate gel containing organic or organometallic molecules that are expected to be incorporated within the interlayer space. Complete crystallization occurs upon aqueous reflux for 48 h. The progress of clay layer formation was monitored by X-ray powder diffraction (XRD), differential thermal gravimetry (DTG), and infrared (IR) spectroscopy. Evidence of clay XRD peaks occurs after just 4 h of hydrothermal treatment, and Mg(OH)2 is no longer observable after 14 h. Observable changes in DTG and IR occur at about this time as well. Warren line-shape analysis of the 110 reflection indicates that when growth is complete the clay lamellae are on average ∼50% and 25% of the size of natural hectorites and montmorillonites, respectively. The N2 BET surface areas for all materials are also compared. Small angle neutron scattering shows that addition of tetraethyl ammonium (TEA) ions does not alter the structural integrity over that of the purely inorganic form of Li-hectorite, but that use of a cationic polymer does significantly alter the microstructure. The effect of temperature is critical, for at room temperature only the layered Mg hydroxide mineral brucite crystallizes unless very long time scales are used. The crystallizations carried out at room temperature show that clay will form after about 3 months, but that the presence of organics (at least TEA) acts to hinder this process greatly. The role of the organic molecules on silicate clay layer formation is compared with the role of organics in zeolite synthesis.


Author(s):  
Deborah Cosentini ◽  
Salvatore Grisanti ◽  
Julien Hadoux ◽  
Rossella Libè ◽  
Michele Frigerio ◽  
...  

Abstract Context patients with adrenocortical carcinoma (ACC) are frequently on mitotane therapy for a long-time period. The drug exerts an adrenolytic activity requiring glucocorticoid supplementation, which can be potentially detrimental for bone. Objectives to explore whether mitotane plus/minus chemotherapy is associated with an increased proportion of morphometric vertebral fractures (VFs) in ACC patients. Secondary objectives were: proportion of patients with VF progression, or worsening of the spinal deformity index (SDI) during mitotane therapy; predictive factors of VF progression and prognostic role of VF progression. Design and setting multicenter, retrospective cohort study of patients with ACC who received mitotane alone or in association to chemotherapy, recruited from January 2010 to January 2020 in two reference centers in Italy and France. Results a significant increase in the frequency of VFs before and after mitotane therapy was seen both in Italian (28.3% vs 47.8%, p: 0.04) and French (17.8% vs 35.6%, p 0.04) series. VF progression was observed in 39.1%, and 28.9% of patients, respectively. Baseline VFs and increased patient body mass index, but not the dose of cortisol supplementation, showed an independent association with VF progression at multivariate analysis. Among the 72 advanced ACC patients, progression of VFs was associated with a poorer survival. Conclusions the administration of mitotane plus/minus chemotherapy in ACC patients impairs bone health independently from cortisol supplementation. Appropriate preventive measures to decrease the fracture risk should be implemented in these patients.


2022 ◽  
Vol 8 (1) ◽  
pp. 76-80
Author(s):  
F. Agayev

All over the planet, potatoes are an important staple food crop. However, to maintain the quality of the tubers and increase their availability, it is necessary to store the tubers for a long time, often using industrial scale equipment. In this context, maintaining potato quality is critical for the seed, fresh and processing sectors. The industry has always innovated and invested in improved post-harvest storage. However, the rate of technological change is accelerating and will continue to accelerate. Stricter legislation and changing consumer attitudes are driving increased interest in creating alternative or complementary post-harvest treatments to traditional growth suppression and disease control chemicals. We are considering modern knowledge about the biochemical factors that determine the state of dormancy, as well as the influence of factors before and after harvest on ensuring the quality of potato tubers. In addition, the role of genomics as a future approach to improving potato quality is discussed. It is critical, thanks to more focused industry research, to understand how pre-harvest conditions affect tuber quality and the factors that determine the transition to dormancy, which should create the conditions for achieving sustainable storage.


Crisis ◽  
2010 ◽  
Vol 31 (3) ◽  
pp. 160-164 ◽  
Author(s):  
Almir Fajkic ◽  
Orhan Lepara ◽  
Martin Voracek ◽  
Nestor D. Kapusta ◽  
Thomas Niederkrotenthaler ◽  
...  

Background: Evidence on youth suicides from Southeastern Europe is scarce. We are not aware of previous reports from Bosnia and Herzegovina, which experienced war from 1992 to 1995. Durkheim’s theory of suicide predicts decreased suicide rates in wartime and increased rates afterward. Aims: To compare child and adolescent suicides in Bosnia and Herzegovina before and after the war. Methods: Data on youth suicide for prewar (1986–90) and postwar (2002–06) periods were analyzed with respect to prevalence, sex and age differences, and suicide methods. Suicide data from 1991 through 2001 were not available. Results: Overall youth suicide rates were one-third lower in the postwar than in the prewar period. This effect was most pronounced for girls, whose postwar suicide rates almost halved, and for 15–19-year-old boys, whose rates decreased by about a one-fourth. Suicides increased among boys aged 14 or younger. Firearm suicides almost doubled proportionally and were the predominant postwar method, while the most common prewar method had been hanging. Conclusions: The findings from this study indicate the need for public education in Bosnia and Herzegovina on the role of firearm accessibility in youth suicide and for instructions on safe storage in households. Moreover, raising societal awareness about suicide risk factors and suicide prevention is needed.


2008 ◽  
pp. 61-76
Author(s):  
A. Porshakov ◽  
A. Ponomarenko

The role of monetary factor in generating inflationary processes in Russia has stimulated various debates in social and scientific circles for a relatively long time. The authors show that identification of the specificity of relationship between money and inflation requires a complex approach based on statistical modeling and involving a wide range of indicators relevant for the price changes in the economy. As a result a model of inflation for Russia implying the decomposition of inflation dynamics into demand-side and supply-side factors is suggested. The main conclusion drawn is that during the recent years the volume of inflationary pressures in the Russian economy has been determined by the deviation of money supply from money demand, rather than by money supply alone. At the same time, monetary factor has a long-run spread over time impact on inflation.


2018 ◽  
Vol 15 (1) ◽  
pp. 55-72
Author(s):  
Herlin Hamimi ◽  
Abdul Ghafar Ismail ◽  
Muhammad Hasbi Zaenal

Zakat is one of the five pillars of Islam which has a function of faith, social and economic functions. Muslims who can pay zakat are required to give at least 2.5 per cent of their wealth. The problem of poverty prevalent in disadvantaged regions because of the difficulty of access to information and communication led to a gap that is so high in wealth and resources. The instrument of zakat provides a paradigm in the achievement of equitable wealth distribution and healthy circulation. Zakat potentially offers a better life and improves the quality of human being. There is a human quality improvement not only in economic terms but also in spiritual terms such as improving religiousity. This study aims to examine the role of zakat to alleviate humanitarian issues in disadvantaged regions such as Sijunjung, one of zakat beneficiaries and impoverished areas in Indonesia. The researcher attempted a Cibest method to capture the impact of zakat beneficiaries before and after becoming a member of Zakat Community Development (ZCD) Program in material and spiritual value. The overall analysis shows that zakat has a positive impact on disadvantaged regions development and enhance the quality of life of the community. There is an improvement in the average of mustahik household incomes after becoming a member of ZCD Program. Cibest model demonstrates that material, spiritual, and absolute poverty index decreased by 10, 5, and 6 per cent. Meanwhile, the welfare index is increased by 21 per cent. These findings have significant implications for developing the quality of life in disadvantaged regions in Sijunjung. Therefore, zakat is one of the instruments to change the status of disadvantaged areas to be equivalent to other areas.


2019 ◽  
Author(s):  
Shuyuan Zheng ◽  
Taiping Hu ◽  
Xin Bin ◽  
Yunzhong Wang ◽  
Yuanping Yi ◽  
...  

Pure organic room temperature phosphorescence (RTP) and luminescence from nonconventional luminophores have gained increasing attention. However, it remains challenging to achieve efficient RTP from unorthodox luminophores, on account of the unsophisticated understanding of the emission mechanism. Here we propose a strategy to realize efficient RTP in nonconventional luminophores through incorporation of lone pairs together with clustering and effective electronic interactions. The former promotes spin-orbit coupling and boost the consequent intersystem crossing, whereas the latter narrows energy gaps and stabilizes the triplets, thus synergistically affording remarkable RTP. Experimental and theoretical results of urea and its derivatives verify the design rationale. Remarkably, RTP from thiourea solids with unprecedentedly high efficiency of up to 24.5% is obtained. Further control experiments testify the crucial role of through-space delocalization on the emission. These results would spur the future fabrication of nonconventional phosphors, and moreover should advance understanding of the underlying emission mechanism.<br>


Author(s):  
Sanjeeva Kumar Goud T ◽  
Rahul Kunkulol

The present study was aimed to study the effect of Sublingual Vitamin D3 on Serum Vitamin D level in Vitamin D deficiency patients. This was a cross-sectional and interventional study. All the Vitamin D deficiency patients of age 18-60years and either gender, willing to participate in the study were included. Patients who had greater than 20 ng/ml were excluded from the study. The total number of participants in our study was 200, out of these 111 males and 89 females, the mean age in our study was 51.07 ± 7.39Yrs. All volunteers were given sublingual vitamin D3 (60,000IU) in six doses every fifteen days of follow up for 3 months. The subject’s serum 25(OH)D levels were estimated before and after the treatment of sublingual vitamin D3. There was a statistically significant difference in serum vitamin D3 level before 16.61±6.71 ng/ml and after 35.80±7.80 ng/ml after treatment with Sublingual Vitamin D3. Six doses of 60,000IU of Vitamin D3 sublingual route having improved the role of serum 25(OH)D levels in the treatment of Vitamin D3 deficiency patients.Keywords: Vitamin D3; Sublingual route


Author(s):  
М. В. Дзисюк

Definitions of concept and sphere of the concept are widely used in different aspects of modern linguistics. There is no single understanding of these notions and universal methodology of research has not been invented by linguists yet. This predetermines topicality of the article. The aim of our research is analysis, generalization, and systematization of different approaches to the interpretation of the notion ‘concept’ that exist in modern linguistics. It results in the following tasks: analysis of existing definitions of concept and its division into certain ranges and defining classification features. Modern linguists raise the questions of the conceptual and linguistic image of the world, the role of a human factor in its formation and interaction as in a linguistic process more frequently and it is defined as a fact in today’s linguistic scientific literature. The problem of individual language formation, poetic one in particular gains important meaning in this context. Ukrainian linguists use the notion of ‘concept’ for a long time now although they adhere to different views on its definition. Researches of the question define two major approaches in the analysis of the notion ‘concept’ that is linguistic-cognitive and linguistic-cultural. We can claim that words-concepts are agents between material reality and the ideal world that is synthesized in poetry, carriers of sense since with their help the versatility of the real world correlates with eternal spiritual values. Therefore, main features of the notion ‘concept’ in which objectively-cognitive and subjectively-creative features are combines are as follow sensual authenticity, time-spatial features, mediation between material and spiritual, semantic filling, ability to polysemy. A word with a generally symbolic meaning that is implemented in a language process through literary techniques typical for poet’s idiotype is the main core of the concept. The concept in poetic language formation by modern Uman poets is semantically integral, fulfilled, able to penetrate into other concepts and absorb semantically narrower images saving unity and semantic independence, varying numerous interpretations that project it in a certain semantic space, saving potential of real reflection.


2018 ◽  
Vol 69 (8) ◽  
pp. 2232-2235
Author(s):  
Marius Moga ◽  
Mark Edward Pogarasteanu ◽  
Antoine Edu

The role of arthroscopy in incipient and mild arthrosis, even combined with proximal tibial ostetomy, is well known and well documented. On the other hand, its role in the treatment of advanced arthrosis of the large joints, especially the knee, is a subject of controversy. The proponents of the use of arthroscopy in advanced arthrosis claim that meniscectomy, synovectomy, ostophytectomy, chondral lesion stabilization, arthroscopic release, plica and loose body removal greatly improve the quality of life for most patients, especially if followed by the use of viscoelastic injection, by diminishing pain and improving joint range of motion. The opponents claim that, even though the advantages are clear in the cases that refuse arthroplasty, in all the other cases the surgical indication should be total knee arthroplasty, as the clinical relief is temporary, but with all the risks of a surgical intervention. We have conducted an overview of the recent literature, in order to find objective evidence to sustain either point of view. We focused on articles published that included an objective measurement of before and after clinical status through clinical scores and objective measurements. We also focused on the follow-up period and on the evolution of the pathology after arthroscopy.


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