A Comparative Study of Mechanical Properties in Ion-Irradiated A12O3 and MgO·nAl203

1998 ◽  
Vol 540 ◽  
Author(s):  
K. Yasuda ◽  
C. Kinoshita ◽  
K. Izumi
Keyword(s):  
Mechanical Properties ◽  
Comparative Study ◽  
Lattice Constant ◽  
Point Defects ◽  
Recombination Rate ◽  
Radiation Hardening ◽  
Maximum Value ◽  
Plastic Hardening ◽  
Load Displacement ◽  
The Difference

AbstractWe have investigated radiation hardening in alumina (A1203), stoichiometric and nonstoichiometric spinel (MgO·nA1203: n= 1, 2.4) crystals at 300 K irradiated with 100 keV He+ ions by using a ultra-microhardness technique. Al203 shows a remarkable radiation hardening (35% increase in hardness) at a fluence of 5×1019 He+/m2 and saturates at 60 % of the maximum value at fluences higher than 8×1019 He+/m2. In spinel crystals, hardness increases monotonically with fluence, reaching to a saturation at a fluence of 1×1020He+/m2. Analyses of load- displacement curves indicate that both plastic and elastic hardening are responsible for the radiation hardening in A1203, and that plastic hardening is the main cause in MgO'nAl2O3. Microstructure observations and lattice constant measurements showed that point defects are mainly responsible for the radiation hardening in both A1203 and MgO·nAl2O3. The difference in the radiation hardening response is discussed in terms of the difference in recombination rate of point defects among the MgO-A1203 system ceramics.

scholarly journals Preparation of Three Types of Transformer Oil-Based Nanofluids and Comparative Study on the Effect of Nanoparticle Concentrations on Insulating Property of Transformer Oil

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Qi Wang ◽  
Muhammad Rafiq ◽  
Yuzhen Lv ◽  
Chengrong Li ◽  
Kai Yi
Keyword(s):  
Thermal Properties ◽  
Comparative Study ◽  
Breakdown Voltage ◽  
Breakdown Strength ◽  
Transformer Oil ◽  
Standard Methods ◽  
Maximum Value ◽  
Negative Impulse ◽  
The Difference

Nanofluids have the potential to become the alternatives of conventional transformer oil for their exquisite electrical and thermal properties. Three kinds of nanoparticles with distinct conductivities, namely, nonconductive nanoparticle Al2O3, conductive nanoparticle Fe3O4, and semiconductive nanoparticle TiO2, with different concentrations from 5% to 40% w/v were selected and suspended into transformer oil to develop nanofluids. The lightening impulse breakdown strengths of the oil samples with and without nanoparticles were measured according to IEC standard methods. The positive impulse breakdown strength indicated that breakdown strength is first increased up to the maximum value at certain concentration and then starts decreasing. The results of negative impulse breakdown manifested that the breakdown voltages of nanofluids with different concentrations were less than the breakdown voltage of pure transformer oil. Different effect mechanisms of dielectric and conductive nanoparticles were also used to describe the difference among three prepared nanofluids.

Comparative Study of Size, Total Protein, Fibrinogen and 5-HT Content of Human and Canine Platelet Density Subpopulations

1986 ◽  
Vol 56 (03) ◽  
pp. 288-292 ◽  
Author(s):  
Diego Mezzano ◽  
Eduardo Aranda ◽  
Arnaldo Foradori
Keyword(s):  
Comparative Study ◽  
Protein Content ◽  
Cell Density ◽  
Total Protein ◽  
Unit Volume ◽  
Low Density ◽  
Dense Bodies ◽  
Artifactual Changes ◽  
Platelet Release ◽  
The Difference

SummaryThe size, total protein, fibrinogen and 5-HT content were evaluated in density subpopulations of human and canine platelets fractionated in linear arabinogalactan gradients. The methodology was assessed to ascertain that platelet separation was by density and to discard artifactual changes and platelet release during the procedure. EDTA or PGEi increased the size of human PRP-platelets, but not of dog platelets. In humans, high density (HD) platelets were 1.26 times larger and contained 1.88 times more fibrinogen, 2.23 times more 5-HT and 1.37 times more protein than low density (LD) platelets; in dogs, these density cohorts did not differ in protein content, but LD platelets were 1.29 times larger and had 1.33 times more fibrinogen and 5-HT than HD platelets. These findings suggest that cell density is mostly dependent on the protein content per unit volume of platelets (and not on dense bodies). The differences in fibrinogen and 5-HT content between HD and LD cohorts in humans and dogs may be related to platelet age. The difference in volume between HD and LD platelets in dogs is of uncertain interpretation.

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Pandhawa Gubah sebagai Representasi Interaksi Metafisik Manusia Jawa dan Perbandingannya dengan Cheritera Pandawa Lima

Manuskripta ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
Novarina Novarina
Keyword(s):  
Comparative Study ◽  
Literary Theory ◽  
Research Method ◽  
Descriptive Analysis ◽  
Literary Study ◽  
Analysis Method ◽  
Research Objects ◽  
Similarities And Differences ◽  
The Difference ◽  
The Comparative Study

Abstract: This research is a comparative literary study that uses Malay and Javanese versions of Mahabarata text sources. The research objects used were the text edition of Pandhawa Gubah (PG) by Sudibjo Z. Hadisutjipto and the text of Cheritera Pandawa Lima (CPL) by Khalid Hussain. The research method used is descriptive-analysis method. In the comparative study used a comparative literary theory proposed by Endraswara (2011). The results of the text comparison reveal the similarities and differences in the image of Bima figures in the Javanese and Malay versions. The equation as a whole is that both texts contain the same heroic storyline and heroic character, Bima. In addition, Indian influence is still evident in the two texts seen from the nuances of Hinduism that exist in both texts. While the difference is seen in the events that accompany Bima's struggle in achieving his victory. Based on these similarities and differences, it can be seen that the authors attempt to represent the concept of metaphysical interactions vertically and horizontally expressed through PG text. --- Abstrak: Penelitian ini adalah satu kajian sastra bandingan yang menggunakan sumber teks Mahabarata versi Melayu dan Jawa. Objek penelitian yang digunakan adalah edisi teks Pandhawa Gubah (PG) karya Sudibjo Z. Hadisutjipto dan teks Cheritera Pandawa Lima (CPL) karya Khalid Hussain. Metode penelitian yang digunakan adalah metode deskriptif-analisis. Dalam telaah perbandingan digunakan teori sastra bandingan yang dikemukakan Endraswara (2011). Hasil perbandingan teks mengungkapkan adanya persamaan dan perbedaan citra tokoh Bima dalam versi Jawa maupun versi Melayu. Persamaan secara keseluruhan adalah kedua teks tersebut mengandung alur cerita kepahlawanan dan tokoh pahlawan yang sama yaitu Bima. Selain itu, pengaruh India masih tampak dalam kedua teks tersebut dilihat dari nuansa Hinduisme yang ada dalam kedua teks. Sementara perbedaannya tampak pada peristiwa-peristiwa yang menyertai perjuangan Bima dalam mencapai kemenangannya. Berdasarkan persamaan dan perbedaan tersebut tampak adanya upaya penulis untuk merepresentasikan konsep interaksi metafisik secara vertikal dan horizontal yang diungkapkan melalui teks PG.

Being Mother:Comparative Study of the Contested Motherhood between South Korea and Indonesia

2018 ◽  
Vol 1 (1) ◽  
pp. 22
Author(s):  
Desintha Asriani
Keyword(s):  
Political Economy ◽  
South Korea ◽  
Comparative Study ◽  
Cultural Issues ◽  
Family Routine ◽  
The Difference

This paper attempts to explain the discourse of motherhood in both South Korea and Indonesia. It is based on the interesting dynamic of being mother that is much influenced by the interrelated actions played by number of dominant actors around woman itself. By using a comparative study, it is found that the map or the trace of political economy in terms of developmental agenda, in fact drives the difference flows in shaping the notion of motherhood. In Indonesia, for being mother, women exist in the intersection of state intention, industrialization and culture pressure. Indonesian motherhood is interestingly in line with another analysis, such in their relation with housemaids. Meanwhile, in South Korea, the description of motherhood occurs in the middle of nationalism spirit, competition, ambience and family routine. Hence, this study concludes that being mother is highly contested and closely associated with the endless structural and cultural issues.

scholarly journals Interfacial Strengthening of Graphene/Aluminum Composites through Point Defects: A First-Principles Study

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 738
Author(s):  
Xin Zhang ◽  
Shaoqing Wang
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix Composites ◽  
Point Defects ◽  
Metal Matrix ◽  
Interfacial Bonding ◽  
Theoretical Research ◽  
Matrix Composites ◽  
Aluminum Composites ◽  
Single Vacancy ◽  
Design Guideline

The relationship between point defects and mechanical properties has not been fully understood yet from a theoretical perspective. This study systematically investigated how the Stone–Wales (SW) defect, the single vacancy (SV), and the double vacancy (DV) affect the mechanical properties of graphene/aluminum composites. The interfacial bonding energies containing the SW and DV defects were about twice that of the pristine graphene. Surprisingly, the interfacial bonding energy of the composites with single vacancy was almost four times that of without defect in graphene. These results indicate that point defects enhance the interfacial bonding strength significantly and thus improve the mechanical properties of graphene/aluminum composites, especially the SV defect. The differential charge density elucidates that the formation of strong Al–C covalent bonds at the defects is the most fundamental reason for improving the mechanical properties of graphene/aluminum composites. The theoretical research results show the defective graphene as the reinforcing phase is more promising to be used in the metal matrix composites, which will provide a novel design guideline for graphene reinforced metal matrix composites. Furthermore, the sp3-hybridized C dangling bonds increase the chemical activity of the SV graphene, making it possible for the SV graphene/aluminum composites to be used in the catalysis field.

scholarly journals Correlating point defects with mechanical properties in nanocrystalline TiN thin films

2021 ◽  
pp. 109844
Author(s):  
Zaoli Zhang ◽  
Arsham Ghasemi ◽  
Nikola Koutná ◽  
Zhen Xu ◽  
Thomas Grünstäudl ◽  
...  
Keyword(s):  
Thin Films ◽  
Mechanical Properties ◽  
Point Defects ◽  
Tin Thin Films

scholarly journals Goldmann Tonometry and Corneal Biomechanics

2021 ◽  
Vol 11 (9) ◽  
pp. 4025
Author(s):  
Dario Messenio ◽  
Marco Ferroni ◽  
Federica Boschetti
Keyword(s):  
Mechanical Properties ◽  
Anterior Chamber ◽  
Pressure Transducer ◽  
Pearson Correlation ◽  
Corneal Thickness ◽  
Applanation Tonometry ◽  
In Vitro Tests ◽  
Goldmann Tonometry ◽  
The Difference

Glaucoma is the second cause of irreversible blindness in the world. Intraocular pressure (IOP) is a recognized major risk factor for the development and progression of glaucomatous damage. Goldmann applanation tonometry (GAT) is internationally accepted as the gold standard for the measurement of IOP. The purpose of this study was to search for correlations between Goldmann tonometry and corneal mechanical properties and thickness by means of in vitro tests. IOP was measured by the Goldmann applanation tonometer (GIOP), and by a pressure transducer inserted in the anterior chamber of the eye (TIOP), at increasing pressure levels by addition of saline solution in the anterior chamber of enucleated pig eyes (n = 49). Mechanical properties were also determined by inflation tests. The GAT underestimated the real measurements made by the pressure transducer, with most common differences in the range 15–28 mmHg. The difference between the two instruments, highlighted by the Bland–Altman test, was confirmed by ANOVA, normality tests, and Mann–Whitney’s tests, both on the data arranged for infusions and for the data organized by pressure ranges. Pearson correlation tests revealed a negative correlation between (TIOP-GIOP) and both corneal stiffness and corneal thickness. In conclusion, data obtained showed a discrepancy between GIOP and TIOP more evident for softer and thinner corneas, that is very important for glaucoma detection.

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