Elastoplastic stress analysis of functionally graded disc under internal pressure– complas XII

The study deals with elastoplastic stress analysis of a hollow disk made of functionally graded materials (FGMs) subjected to an internal pressure. The material properties of disc are assumed to vary radially according to power law function, but Poisson’s ratio is taken constant. Small deformations and a state of plane stress are presumed, and the analysis of disk is based on Von-Mises yield criterion. The materials are assumed to be linear strain hardening, isotropic and not be affected by temperature. Variation of stresses and displacements according to gradient parameters are investigated by using analytical and finite element method. The results show that gradient parameters have an important role in determining the elastoplastic stress of functionally graded disc

Determination of nitrate and nitrite content of Turkish cheeses

The levels of nitrate and nitrite were determined in 185 samples of Turkish cheese having high consumption rate. All cheese samples contained nitrate and its level in Turkish white cheese produced from cow’s and sheep’s milk were found between 0.92 - 22.40 (mean 8.96±4.93) mg/kg and 0.47 - 23.68 (mean 12.35±6.28) mg/kg, respectively. Nitrate level in fresh kasar cheese and mature kasar cheese samples were 0.68 - 17.19 (mean 8.97±5.03) mg/kg and 1.76 - 13.31 (mean 9.45±4.03) mg/kg, respectively. Nitrite was detected 88.11% of cheese samples and mean nitrite values were found between 0.88- 1.64 mg/kg. The highest levels of nitrate and nitrite were determined in the Turkish white cheese samples produced from sheep’s milk. The nitrate content of the examined samples of Turkish cheese could be attributed to both external sources such as contamination by nitrate fertilizers, forage, and agricultural drinking water and addition of nitrate to the cheese milk. It is suggested that stricter control of nitrate in cheese is necessary, and that it should not be used to mask poor hygienic conditions during manufacturing. Hygienic condition must be kept at excellent level in related industrie

Cranial magnetic resonance imaging as a screening tool for evaluation of silent brain ischemia in severe coronary artery disease: A clinical based study

Aim: Silent brain ischemia (SBI), defined as ischemic changes and infarcts without neurologic signs, is an established marker of poor survival. Magnetic resonance imaging (MRI) is useful to define SBI and white matter hyperintensities that correspond to microangipathic ischemic disease. This study aimed to investigate the relationship among SBI, white matter lesions and the extent of coronary artery disease (CAD), and to determine possible predictors of SBI. Material and Methods: A total 10640 patients who underwent coronary angiography were retrospectively screened to reveal 312 patients who had been evaluated with a subsequent cranial MRI within 6 months. CAD severity was established with Gensini score and MRIs were evaluated to determine presence of SBI and white matter hyperintensities scored by Fazekas. Finally, 58 patients with SBI and 254 without SBI consisted SBI and non-SBI groups. Results: Patients with SBI were significantly older with higher prevalence of male gender than the non-SBI patients. Both Gensini and Fazekas scores were higher in SBI-group (p<0.001). Fazekas score was positively correlated with Gensini score (r=0.219, p<0.001) and age (r=0.465, p<0.001). In the logistic regression analysis; age, male gender and Gensini score were identified as the independent predictors of SBI. Conclusion: Although SBIs don’t present neurological symptoms they are associated with poor survival and future stroke. Our data suggest that cranial MRI may be a screening tool in risk stratification, particularly in elderly male patients with multivessel CAD. Our study also depicted that age, male gender and high Gensini scores are the independent predictors of SBI. © 2020, Duzce University Medical School. All rights reserved

What Is the Important Point Related to Follow-Up Sonographic Evaluation for the Developmental Dysplasia of the Hip?

Developmental dysplasia of the hip (DDH) is an important cause of childhood disability. Subluxation or dislocation can be diagnosed through pediatric physical examination; nevertheless, the ultrasonographic examination is necessary in diagnosing certain borderline cases. It has been evaluated routine sonographic examination of 2,444 hips of 1,222 babies to determine differences in both, developmental dysplasia and types of hips, and evaluated their development on the 3-month follow-up. Evaluating the pathologic alpha angles under 59, there was no statistically significant differences between girls and boys in both right (55.57 +/- 3.73) (56.20 +/- 4.01), (p = 0.480), and left (55.79 +/- 3.96) (57.00 +/- 3.84), (p = 0.160) hips on the 45th day of life. Routine sonographic examinations on the 45th day of life revealed that 51 of (66.2%) 77 type 2a right hips were girls and 26 (33.8%) were boys. The number of the right hips that develop into type 1 was 38 (74.5%) for girls and 26 (100%) for boys on the 90th day of life (p = 0.005). A total of 87 type 2a left hips included 64 girls (73.6%) and 23 boys (26.4%). In the 90th day control, 49 right hip of girls (76.6%) and 21 right hip of boys (91.3%) developed into type 1 (p = 0.126). In the assessment of both left and right hips, girls showed a significantly higher frequency in latency and boys showed significantly higher development in the control sonography. A total of 31 girls (2.5%) and 11 boys (0.9%) accounted for a total of 42 (3.4%) cases who showed bilateral type 2a hips in 1,222 infants. On the 90th day control, 26 girls (83.9%) and all 11 boys (100%) developed into type 1 (p = 0.156). The study emphasizes the importance of the sonographic examination on the 90th day of life. Results of the investigation include the data of sonographic screening of DDH on the 45th day, and also stress the importance of the 90th-day control sonography after a close follow-up with physical examination between 45th and 90th days of life

Towards an Architecture Proposal for Federation of Distributed DES Simulators

The simulation of large and complex Discrete Event Systems (DESs) increasingly imposes more demanding and urgent requirements on two aspects accepted as critical: (1) Intensive use of models of the simulated system that can be exploited in all phases of its life cycle where simulation can be used, and methodologies for these purposes; (2) Adaptation of simulation techniques to HPC infrastructures, as a method to improve simulation efficiency and to have scalable simulation environments. This paper proposes a Model Driven Engineering approach (MDE) based on Petri Nets (PNs) as formal model. This approach proposes a domain specific language based on modular PNs from which efficient distributed simulation code is generated in an automatic way. The distributed simulator is constructed over generic simulation engines of PNs, each one containing a data structure representing a piece of net and its simulation state. The simulation engine is called simbot and versions of it are available for different platforms. The proposed architecture allows, in an efficient way, a dynamic load balancing of the simulation work because the moving of PN pieces can be realized by moving a small number of integers representing the subnet and its state

Kersetinin Ratlarda, Yanık Staz Bölgesi Üzerindeki Etkisi

Yanık tedavisinde esas amaç hasarlanan doku miktarının minimal seviyede tutmaktır. Yanık alanın genişlik ve derinliğinin miktarı hastaların mortalite ve morbiditesini belirleyen temel faktördür. Staz zonu olarak tanımlanan ve koagulasyon alanını çevreleyen alan yanık sonrası oluşacak nekrozun derinlik ve genişliğini belirleyen kritik bölgedir. Birçok ajan staz zonundaki dokularının korunması için denenmiştir. Bu deneysel çalışmada birçok değişik doku üzerinde antioksidan, antiinflamatuar ve antiapoptotik etkisi olduğu bilen kersetinin yanık staz zonu üzerindeki etkisi incelenmektedir. Çalışmada kersetin tedavisi yapılmayan, akut(yanık sonrası tedaviye başlanan) kersetin tedavisi yapılan ve kronik(yanık öncesi tedaviye başlanan) kersetin tedavisi yapılan gruplar karşılaştırıldı. Tedavi sonrası yanık yarası genişliği planimetrik ve sintigrafik olarak değerlendirildi. Ek olarak doku örnekleri alınarak malondialdehyde(MDA), myeloperoksidaz(MPO) ve nitrotirozin seviyeleri, kersetinin antiinflamatuar ve antioksidan etkisinin gösterilmesi için ölçüldü ve doku örneklerinde apoptoz ve otofaji seviyesi belirlendi. Kersetin ile tedavi edilen gruplarda nekroz miktarının ve apoptozun kontrole göre istatistiksel olarak anlamlı olacak şekilde daha az olduğu, otofajinin de kontrol grubunda, kersetin ile tedavi edilen gruplara göre istatistiksel olarak anlamlı olacak şekilde daha fazla olduğu görüldü. MDA,MPO and nitrotirozin ölçüm değerlerini bakımında gruplar arasında istatistiksel olarak anlamlı olacak şekilde bir fark tespit edilmedi. Sonuç olarak bu çalışma da kersetinin staz zonu üzerinde koruyucu etkisi olduğunu göstermiştir.Keeping the amount of damaged tissue at a minimum is one of the primary goals of treatment in burns. The width and depth of the burned area is at the top of the factors affecting mortality and morbidity in patients.The zone of stasis, the encircling area of the zone of coagulation, is a critical area which determines the depth and width of the necrosis in burns. Many agents were proposed to salvage the zone of stasis. Due to the known antioxidant, antiinflammatory and antiapoptotic effects of quercetin on multiple tissue, the effect of quercetin on saving the zone of stasis was investigated in this experimental study. No quercetin treatment, acute (treatment started after burn injury) quercetin treatment and chronic(treatment started before burn injury) quercetin treatment was compared in a rat comb-burn model. The extent of burn wounds was evaluated by planimetry and scintigraphy in the groups. Additionally, skin samples were obtained to analyze malondialdehyde (MDA), myeloperoxidase (MPO), nitrotyrosine to see antiinflamatuary and antioxidant effect of quercetin and apoptosis and autophagy levels were evaluate. Necrosis rate and apoptosis were statisticaly significant lower in quercetin treatment groups and autophagy level were statisticaly significant lower in control group. There were no difference between the groups in terms of MDA,MPO and nitrotyrosine concentrations. In conclusion, this study showed us the possible saving effect of quercetin on the zone of stasis

Search For Trapped Antihydrogen

We present the results of an experiment to search for trapped antihydrogen atoms with the ALPHA antihydrogen trap at the CERN Antiproton Decelerator. Sensitive diagnostics of the temperatures, sizes, and densities of the trapped antiproton and positron plasmas have been developed, which in turn permitted development of techniques to precisely and reproducibly control the initial experimental parameters. The use of a position-sensitive annihilation vertex detector, together with the capability of controllably quenching the superconducting magnetic minimum trap, enabled us to carry out a high-sensitivity and low-background search for trapped synthesised antihydrogen atoms. We aim to identify the annihilations of antihydrogen atoms held for at least 130 ms in the trap before being released over ~30 ms. After a three-week experimental run in 2009 involving mixing of 10^7 antiprotons with 1.3 10^9 positrons to produce 6 10^5 antihydrogen atoms, we have identified six antiproton annihilation events that are consistent with the release of trapped antihydrogen. The cosmic ray background, estimated to contribute 0.14 counts, is incompatible with this observation at a significance of 5.6 sigma. Extensive simulations predict that an alternative source of annihilations, the escape of mirror-trapped antiprotons, is highly unlikely, though this possibility has not yet been ruled out experimentally.Comment: 12 pages, 7 figure

Fatigue limit of recycled aggregate concrete

This paper presents the main results of the research carried out to obtain the fatigue limit of concrete incorporating recycled aggregate from concrete. In this research, recycled aggregate concretes with partial and total coarse aggregate replacement and control concretes with different increasing water/cement ratios have been cast to study the material’s behavior in response to repeated compressive loads. The results show that, for the same water/cement ratio, the recycled aggregate concretes present a loss of stiffness higher than the control concrete. Furthermore, the use of recycled aggregate in concrete implies a reduction of the fatigue life. These differences are increased for low water/cement ratios, as in this case the main factor is the lower strength capacity of the aggregate. From the results obtained, recommendable mixtures for recycled aggregates exposed to fatigue loads are proposed

Polarimetric interferometer for nanoscale positioning applications

International audienceWe propose and demonstrate a displacement control method at the subnanometric scale based on a Michelson interferometer combined with a polarimeter and a phase-locked loop electronic board. Step by step displacements with a step value of 5 nm are presented. A repeatability of 0.47 nm is obtained from back and forth displacements over 1 m range. We show that a residual ellipticity of less than 10° on the polarization state leads to a positioning error of less than 1 nm. Such system could be used over millimeter range displacements in a controlled surrounding environment leading to numerous applications in nanometrology

Secondary students' values and perceptions of science-related careers: responses to vignette-based scenarios

There has been concern about the attractiveness of science-based careers to many adolescent learners, and it has been suggested that school science may not always recognise or engage personal values that are important to young people in making life choices. The present study discusses interview comments made by upper secondary level students in England when 15 young people were asked to give their personal responses to brief vignettes describing scientific careers. Using an interview-about-scenarios approach, the students were asked about whether they would feel comfortable working in the scientific careers represented. The career areas were purposefully selected because they might be considered to potentially raise issues in relation to personal values or commitments that some students might hold. A range of student perceptions relating to the mooted careers were elicited (positive, negative and indifferent), but all of the participants raised issues that impacted on the acceptability or attractiveness of at least one of the mooted scientific careers, in terms of aspects of their own personal beliefs and values systems. It is recommended that teachers and career advisors should be aware of the range of value-related considerations that influence student views of science-related careers and should consider exploring aspects of science-based careers that link to values commonly shared by young people. This exploratory study also offers indications for directions for further research exploring how learners' value systems impact upon their perceptions of science and scientific work