scholarly journals Tensile Testing with Cyclic Strain Holding to Analyze Dynamic Recrystallization of Pure Lead

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Mayu Muramatsu ◽  
Motomichi Koyama ◽  
Ikumu Watanabe
Keyword(s):  
Dynamic Recrystallization ◽  
Tensile Testing ◽  
Cyclic Strain ◽  
Tensile Tests ◽  
Pure Lead ◽  
Factors Affecting ◽  
Before And After ◽  
Dynamic Recrystallization Behavior ◽  
The Difference ◽  
Strain Responses

We analyzed the dynamic recrystallization of pure lead by tensile testing with cyclic strain holding at room temperature. The specimens were held at an identical strain and subsequently reloaded, providing the strength before and after the strain holding process. The difference in strength enables factors affecting dynamic recrystallization behavior to be analyzed through mechanical testing. For instance, the effects of strain rate on dynamic recrystallization were analyzed by comparing the results obtained from tensile tests with and without strain holding. This experimental technique demonstrated some parts of contribution of elastic strain, dynamic recovery, dynamic recrystallization, and necking to stress-strain responses.

Mechanical strain increases cell stiffness through cytoskeletal filament reorganization

2003 ◽  
Vol 285 (2) ◽  
pp. L456-L463 ◽  
Author(s):  
Paul G. Smith ◽  
Linhong Deng ◽  
Jeffrey J. Fredberg ◽  
Geoffrey N. Maksym
Keyword(s):  
Mechanical Strain ◽  
Cyclic Strain ◽  
Cell Stiffness ◽  
Cytoskeletal Reorganization ◽  
Airway Narrowing ◽  
Cytoskeletal Filament ◽  
Before And After ◽  
The Difference ◽  
And Control

We tested the hypothesis that cytoskeletal reorganization induced by cyclic strain increases cytoskeletal stiffness (G′). G′ was measured by optical magnetic twisting cytometry in control cells and cells that had received mechanical strain for 10–12 days. G′ was measured before and after both contractile and relaxant agonists, and in the strained cells both parallel (Para) and perpendicular (Perp) to the aligned cytoskeleton. Before activation, G′ Para was 24 ± 5% (± SE) greater compared with Perp ( P < 0.05), and 35% ± 6 greater compared with control (Cont, P < 0.01). The difference between strained and control cells was enhanced by KCl, increasing G′ 171 ± 7% Para compared with 125 ± 6% Perp and 129 ± 8% Cont ( P < 10-5 both cases). The decrease in G′ from baseline due to relaxant agonists isoproterenol and dibutyryl cAMP was similar in all groups. Long-term oscillatory loading of airway smooth muscle (ASM) cells caused stiffness to increase and become anisotropic. These findings are consistent with the hypothesis that cytoskeletal reorganization can enhance ASM stiffness and contractility. They imply, furthermore, that oscillatory loading of ASM may contribute to airway narrowing and failure of airway dilation in asthma.

scholarly journals ВЛИЯНИЕ РАЗЛИЧНЫХ ФАКТОРОВ НА МОРФОЛОГИЮ ПОВЕРХНОСТИ ПОКРЫТИЙ ТИПА WC, ОСАЖДЕННЫХ ИОННО-ПЛАЗМЕННЫМ МЕТОДОМ

2018 ◽  
pp. 76-82
Author(s):  
Денис Витальевич Слюсарь ◽  
Владимир Петрович Колесник ◽  
Олег Николаевич Чугай ◽  
Леонид Васильевич Литовченко ◽  
Николай Петрович Степанушкин ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Steel Substrate ◽  
Substrate Material ◽  
Factors Affecting ◽  
Pure Graphite ◽  
Carbide Coatings ◽  
Before And After ◽  
Steel Grades ◽  
Coating Formation ◽  
The Difference

It was studied the morphology of the WС coatings’ surfaces formed by the ion-plasma method on the substrates of БрАЖ9-4 tinless bronze and 12Х18Н9Т stainless steel. Initially, the substrate had the same roughness. The coatings were formed by spraying a lot of cathodes-targets made of BA brand tungsten and ОСЧ 7-3 spectral-pure graphite. The coating thickness was 8 ... 9 μm. The scanning electron microscope РЭМ 106 investigated the surface morphology of various areas of both the substrates and formed coatings. It is revealed the features of the morphology of the substrates and WC coatings’ surfaces determined by the composition of the substrate as well as the remoteness of the investigated area from its edge. It is noted that, regardless of the substrate material, the coatings consist of a multitude of grains, the sizes of which vary in the same limits of 0.5 ... 3 μm. However, in the case of a coating formed on a bronze substrate, grains with a size of 2 ... 3 μm quantitatively predominate. At the same time, the coatings formed on the steel substrate, the size of the predominant grains do not exceed 1 μm. At the edge of the bronze substrate, the grain size varies over a wider range of 0.5 ... 5 μm. The size of the predominant grains is 2 ... 5 μm. It was concluded that one of the main factors affecting the morphology of tungsten carbide coatings is the surface roughness of the substrate based on the analysis of the surface morphology of the substrates before and after their ionic cleaning. That roughness of the substrate arose during its ionic cleaning before forming the coating. Attention is drawn to the fact that the difference in the sputtering coefficients of the elements that form the substrate is of particular importance. This difference in coefficients predetermines the peculiarities of the surface morphology of the substrate after cleaning, which is confirmed by the literature data on the sputtering coefficients of the elements (Fe, Cr, Ni, Ti, Cu, Cu, and Fe) that are part of the applied bronze and steel grades. In addition, the concentration of the electric field at the edge of the substrate plays an important role in cleaning the substrate and coating formation

scholarly journals The effects of “Fangcang, Huoshenshan, and Leishenshan” hospitals and environmental factors on the mortality of COVID-19

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9578
Author(s):  
Yuwen Cai ◽  
Tianlun Huang ◽  
Xin Liu ◽  
Gaosi Xu
Keyword(s):  
Growth Rate ◽  
Air Quality ◽  
Quality Index ◽  
Test Statistic ◽  
Factors Affecting ◽  
Before And After ◽  
The Difference ◽  
Student’S T ◽  
Novel Coronavirus ◽  
Student’S T Test

Background In December 2019, a novel coronavirus disease (COVID-19) broke out in Wuhan, China; however, the factors affecting the mortality of COVID-19 remain unclear. Methods Thirty-two days of data (the growth rate/mortality of COVID-19 cases) that were shared by Chinese National Health Commission and Chinese Weather Net were collected by two authors independently. Student’s t-test or Mann-Whitney U test was used to test the difference in the mortality of confirmed/severe cases before and after the use of “Fangcang, Huoshenshan, and Leishenshan” makeshift hospitals (MSHs). We also studied whether the above outcomes of COVID-19 cases were related to air temperature (AT), relative humidity (RH), or air quality index (AQI) by performing Pearson’s analysis or Spearman’s analysis. Results Eight days after the use of MSHs, the mortality of confirmed cases was significantly decreased both in Wuhan (t = 4.5, P < 0.001) and Hubei (U = 0, P < 0.001), (t and U are the test statistic used to test the significance of the difference). In contrast, the mortality of confirmed cases remained unchanged in non-Hubei regions (U = 76, P = 0.106). While on day 12 and day 16 after the use of MSHs, the reduce in mortality was still significant both in Wuhan and Hubei; but in non-Hubei regions, the reduce also became significant this time (U = 123, P = 0.036; U = 171, P = 0.015, respectively). Mortality of confirmed cases was found to be negatively correlated with AT both in Wuhan (r =  − 0.441, P = 0.012) and Hubei (r =  − 0.440, P = 0.012). Also, both the growth rate and the mortality of COVID-19 cases were found to be significantly correlated with AQI in Wuhan and Hubei. However, no significant correlation between RH and the growth rate/mortality of COVID-19 cases was found in our study. Conclusions Our findings indicated that both the use of MSHs, the rise of AT, and the improvement of air quality were beneficial to the survival of COVID-19 patients.

scholarly journals The Effect of Levator Recession for Upper Eyelid Retraction in Patients with Thyroid-associated Ophthalmopathy

2021 ◽  
Vol 62 (8) ◽  
pp. 1015-1021
Author(s):  
Ja Young Oh ◽  
Jeong Kyu Lee
Keyword(s):  
Medical Records ◽  
Multivariate Logistic Regression Analysis ◽  
Lower Eyelid ◽  
Eyelid Retraction ◽  
Upper Eyelid ◽  
Factors Affecting ◽  
Thyroid Associated Ophthalmopathy ◽  
Before And After ◽  
Upper Eyelid Retraction ◽  
The Difference

Purpose: We analyzed factors that affect the outcome of levator recession surgery for upper eyelid retraction in patients with thyroid-associated ophthalmopathy.Methods: Retrospective analysis was performed based on the medical records of 24 patients with thyroid-associated ophthalmopathy who underwent upper eyelid levator recession surgery between February 10, 2010, and September 18, 2018. The margin to reflex distance (MRD), length and area of the upper and lower eyelids were measured and compared with the eyelid analysis software before and after 6 months of surgery on medical records. In addition, factors affecting the difference in MRD1 before and after surgery were examined by multivariate linear regression analysis.Results: Twenty-four patients were included in the study. The MRD1 decreased significantly from 5.12 ± 1.26 mm before surgery to 3.48 ± 1.08 mm at 6 months after surgery (p < 0.001). All upper eyelid measurements, i.e., UEL (p < 0.001), UMA (p < 0.001), UCA (p = 0.004), and ULA (p < 0.001), were significantly decreased after surgery, while none of the lower eyelid measurements showed significant changes. Multivariate logistic regression analysis indicated that lower preoperative MRD1 was associated with the success of the surgery (odds ratio, 0.31; 95% confidence interval, 0.09-1.01).Conclusions: Levator recession surgery is an efficient surgical method that can correct the upper eyelid retraction associated with thyroid-associated ophthalmopathy.

scholarly journals Mechanical and Microstructural Response of Near Beta Ti Alloys to Hot Tensile Testing

2017 ◽  
Vol 62 (2) ◽  
pp. 815-823
Author(s):  
S.M. Abbasi ◽  
A. Momeni ◽  
M. Daraee ◽  
A. Akhondzadeh ◽  
S.G. Mirsaeed
Keyword(s):  
Dynamic Recrystallization ◽  
Yield Point ◽  
Tensile Testing ◽  
Constant Strain Rate ◽  
Tensile Tests ◽  
Beta Phase ◽  
Alpha Phase ◽  
Hot Ductility ◽  
Ti Alloys ◽  
Negative Effect

AbstractHot tensile tests were carried out on Timetal-125 and Timetal-LCB near beta Ti alloys at temperatures in range of 600-1000°C and constant strain rate of 0.1 s−1. At temperatures below 700-800°C, the homogenuous and total strains for Timetal-LCB were greater than those for Timetal-125. In contrast, at temperatures over 800°C, Timetal-125 showed better hot ductility. The yield point phenomena was observed in Timetal-LCB at all temperatures. Unlikely, for Timetal-125, it was observed only at temperatures over 800°C. The weaker yield point phenomena in Timetal-125 could be attributed to the negative effect of Al on the diffusion of V. At all temperatures Timetal-LCB exhibited higher strength than Timetal-125. It was found that there should be a direct relationship between the extent of yield point phenomena and strength and dynamic softening through hot tensile testing. It was observed that at temperatures beyond 800°C (beta phase field in both alloys) dynamic recrystallization can progress more in Timetal-125 than in Timetal-LCB. These results were in good agreement with the better hot ductility of Timetal-125 at high temperatures. At low temperatures, i.e. below 700-800°C, partial dynamic recrystallization occurs in beta and dynamic globularization in alpha phase. These processes progress more in Timetal-LCB than in Timetal-125.

scholarly journals The Effects of “Fangcang, Huoshenshan, and Leishenshan” Hospitals and Temperature on the Mortality of COVID-19

2020 ◽  
Author(s):  
Yuwen Cai ◽  
Tianlun Huang ◽  
Xin Liu ◽  
Gaosi Xu
Keyword(s):  
Air Temperature ◽  
National Health ◽  
Factors Affecting ◽  
Before And After ◽  
The Difference ◽  
Novel Coronavirus

AbstractBackgroundIn December 2019, a novel coronavirus disease (COVID-19) broke out in Wuhan, China, however, the factors affecting the mortality remain unclear.MethodsThirty-two days of data that were shared by China National Health Commission and China Weather Net were collected using standard forms. The difference in the mortality of confirmed and severe cases before and after the use of “Fangcang, Huoshenshan, and Leishenshan” makeshift hospitals (MSHs) was tested using Mann-Whitney U test. We also studied whether air temperature (AT) could affect the above outcomes of COVID-19 cases by performing Spearman’s analysis.ResultsEight days after the use of MSHs, the mortality of confirmed cases was significantly decreased both in Wuhan (U = 1, P < 0.001) and Hubei (U = 0, P < 0.001), while in non-Hubei regions, as a contrast, the mortality of confirmed cases remained unchanged (U = 40, P = 0.139). However, another eight days later, changes in the mortality in non-Hubei regions also became significant (U = 73, P = 0.039). Mortality of confirmed cases was found to be significantly correlated with AT both in Wuhan (r = −0.441, P = 0.012) and Hubei (r = −0.440, P = 0.012).ConclusionsOur findings indicated that both the use of MSHs and the rise of AT were beneficial to the survival of COVID-19 cases.

scholarly journals The Effect of Material Properties on the Accuracy of Superplastic Tensile Test

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1353
Author(s):  
Sergey Aksenov ◽  
Vadim Mikolaenko
Keyword(s):  
Tensile Test ◽  
Material Properties ◽  
Material Flow ◽  
Tensile Testing ◽  
Flow Behavior ◽  
Effective Strain ◽  
Tensile Tests ◽  
Input Material ◽  
The Difference ◽  
Characterization Of Materials

Tensile testing is widely used for the mechanical characterization of materials subjected to superplastic deformation. At the same time, it is known that the obtained flow data are affected by specimen geometry. Thus, they characterize the specimen rather than the material. This work provides the numerical analysis aimed to study how the material flow behavior affects the results of tensile tests. The simulations were performed by the finite element method in Abaqus software, utilizing user-defined procedures for calculation of forces acting on the crossheads. The accuracy of tensile testing is evaluated by the difference between the input material flow behavior specified in the simulations and the output one, obtained by the standard ASTM E2448 procedure based on the predicted forces. The results revealed that the accuracy of the superplastic tensile test is affected by the material properties. Even if the material flow behavior follows the Backofen power law, which is invariant for the effective strain, the output stress–strain curves demonstrate significant strain hardening and softening effects. The relation between the basic superplastic characteristics and the tensile test errors is described and analyzed.

scholarly journals Analysis of Clinical Characteristics of 52 Patients with Uveitis before and after Vitrectomy and Factors Affecting Clinical Efficacy

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Qian Liu ◽  
Yinghong Zhou ◽  
Hongxia Deng ◽  
Xiaoxia Xiang ◽  
Chaohua Chen ◽  
...  
Keyword(s):  
Influencing Factors ◽  
Clinical Efficacy ◽  
Clinical Characteristics ◽  
Clinical Signs ◽  
Treatment Method ◽  
Posterior Uveitis ◽  
Factors Affecting ◽  
Significant Difference ◽  
Before And After ◽  
The Difference

Objective. To investigate the pre- and postsurgical clinical characteristics and clinical efficacy of patients with uveitis. Methods. The clinical data of patients with uveitis who underwent vitrectomy in our hospital from March 2019 to February 2021 were retrospectively analyzed. There were 52 cases of 64 eyes in total. The data on patient’s gender, age, etiology, course of disease, anatomical classification, number of recurrences, changes in vision before and after surgery, changes in eye signs before and after surgery, and occurrence of postoperative complications were collected. The clinical features before and after vitrectomy were compared, and the influencing factors of clinical efficacy were analyzed. Results. The ocular signs of patients with uveitis after vitrectomy were significantly improved compared with before operation, and the difference was statistically significant ( P < 0.05 ). The visual acuity after vitrectomy in patients with uveitis was significantly improved compared with that before operation, and the difference was statistically significant ( P < 0.05 ). There was no significant difference in the surgical treatment of uveitis patients of different gender, age, and etiology ( P > 0.05 ). There are significant differences in the clinical efficacy of vitrectomy in patients with different anatomical classifications. Among them, patients with panuveitis have the best clinical efficacy with vitrectomy and patients with posterior uveitis have the worst clinical efficacy with vitrectomy ( P < 0.05 ). There is a significant difference in the clinical efficacy of vitrectomy in patients with recurrence times. The lower the number of recurrences, the better the clinical efficacy of vitrectomy in patients ( P < 0.05 ). Conclusion. There are significant differences in the clinical signs of patients with uveitis before and after vitrectomy. Vitrectomy is effective in the treatment of uveitis. The type of anatomy and the number of recurrences are influencing factors for the clinical efficacy of vitrectomy. For patients with posterior uveitis, the surgical method should be carefully considered or a more reasonable treatment method should be selected, and for patients with uveitis with less recurrence, vitrectomy should be considered for active treatment.

Tem analysis of multiple-energy arsenic implanted and Rta'd silicon

1987 ◽  
Vol 45 ◽  
pp. 246-247
Author(s):  
R.A. Herring
Keyword(s):  
Device Fabrication ◽  
High Concentration ◽  
Tem Analysis ◽  
Defect Clusters ◽  
High Fluences ◽  
Small Defect ◽  
Before And After ◽  
The Matrix ◽  
The Difference ◽  
Factor Type

Rapid thermal annealing (RTA) of ion-implanted Si is important for device fabrication. The defect structures of 2.5, 4.0, and 6.0 MeV As-implanted silicon irradiated to fluences of 2E14, 4E14, and 6E14, respectively, have been analyzed by electron diffraction both before and after RTA at 1100°C for 10 seconds. At such high fluences and energies the implanted As ions change the Si from crystalline to amorphous. Three distinct amorphous regions emerge due to the three implantation energies used (Fig. 1). The amorphous regions are separated from each other by crystalline Si (marked L1, L2, and L3 in Fig. 1) which contains a high concentration of small defect clusters. The small defect clusters were similar to what had been determined earlier as being amorphous zones since their contrast was principally of the structure-factor type that arises due to the difference in extinction distance between the matrix and damage regions.

Changes in Platelet Aggregability after Ovariectomy

1979 ◽  
Vol 42 (04) ◽  
pp. 1332-1339 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Takeshi Motomiya ◽  
Minoru Sonoda ◽  
Noboru Miyagawa
Keyword(s):  
Platelet Count ◽  
Platelet Activation ◽  
Ovarian Hormones ◽  
Control Group ◽  
Platelet Aggregability ◽  
Appearance Rate ◽  
Before And After ◽  
The Difference ◽  
Induced Aggregation ◽  
Observation Period

SummaryChanges in platelets in 48 patients with uterine myoma before and after hysterectomy with and without ovariectomy were examined. Bilateral ovariectomy in 25 cases (ovariec-tomized group) and unilateral or non-ovariectomy in 23 cases (control group) were performed at the hysterectomy. Platelet count and an appearance rate of secondary aggregation decreased at one day after and increased at one week after the operation, similarly in both the ovariectomized and the control group. The appearance rate of secondary aggregation was reflected in an intensity of aggregation at 5 min after the addition of reagent to PRP. At one month after the operation, the appearance rate of secondary aggregation induced by 3 μM ADP showed a statistically significant decrease in comparison with the preoperation value (P <0.05) and the enhancement of 5-min aggregation was still observed in the control group, while ceased in the ovariectomized group. The difference between the two groups was significant (P < 0.05). There was almost no change in the speed and intensity of primary and secondary aggregation during the observation period. No significant differences in collagen-induced aggregation were noted between the two groups. The results suggest that ovarian hormones, mainly estrogen, facilitate platelet activation which is mediated by the so-called secondary aggregation.

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