scholarly journals Effects of Gamma Radiation on the Elastic Properties of Thulium Doped Zinc Borotellurite Glass

2017 ◽  
Vol 268 ◽  
pp. 8-12
Author(s):  
Laoding Hasnimulyati ◽  
Mohamed Kamari Halimah ◽  
Zakaria Azmi ◽  
Abdul Halim Shaari ◽  
Mansor Ishak
Keyword(s):  
Gamma Radiation ◽  
Elastic Properties ◽  
Elastic Moduli ◽  
Glass Network ◽  
Ring Size ◽  
Prepared Glass ◽  
Increasing Trend ◽  
Before And After ◽  
Atomic Ring ◽  
Irradiation Process

Effects of gamma radiation on the elastic properties of {[(TeO2)0.7(B2O3)0.3]0.7[ZnO]0.3}0.99{Tm2O3}0.01 (thulium doped zinc borotellurite glass) were investigated. Glass samples were prepared using the melt-quenching technique. Density and ultrasonic velocity of glasses before and after irradiation process were measured using Electronic Densimeter MD-300S and Ritec Ram-5000 Snap System, respectively. Next, elastic moduli and Poisson’s ratio of the glasses were calculated. Atomic ring size of the glass network was also calculated to support the attained results. Results show that density varied after radiation and maximised at 20 kGy. This is attributed to the breaking and rearrangement of chemical bonding in the glass network due to radiation. Furthermore, all elastic parameters exhibited an increasing trend that indicated the strengthening of the glass samples as well as increment of its rigidity. Besides that, atomic ring size was found to decrease as radiation dose increased. This indicate that compaction of glass network took place as the samples were exposed to gamma rays which in turn contributed to the elevation of elastic moduli of the prepared glass.

On the analysis and prediction of elastic properties in alkali Na2O–B2O3–V2O5 glasses under the substitution of V2O5 by Na2O

2019 ◽  
Vol 60 (6) ◽  
pp. 213-221
Author(s):  
Amin Abd El-Moneim ◽  
Hassan Y. Alfifi
Keyword(s):  
Elastic Properties ◽  
Dissociation Energy ◽  
Packing Density ◽  
Poisson’S Ratio ◽  
Elastic Moduli ◽  
Unit Volume ◽  
Dominant Role ◽  
Glass Network ◽  
Poisson's Ratio ◽  
Structural Units

In this article, we have continued our recent work(30,42) on the prediction of elastic properties in alkali borovanadate glasses. Changes in the elastic moduli and Poisson’s ratio due to the substitution of V2O5 by Na2O in the ternary alkali Na2O–B2O3–V2O5 glasses have been analysed and predicted on the basis of the theories and approaches that existing in the field. Both the packing density and dissociation energy per unit volume of the glass were evaluated in terms of the basic structural units that constitute the glass network. In addition to this, the theoretical values of elastic moduli and Poisson’s ratio were calculated from the Makishima–Mackenzie’s model and compared with the corresponding experimental values. The results revealed that the concentrations of the basic structural units BO3, BO4, VO5 and VO4 play a dominant role in correcting the anomalous behaviour between experimental elastic moduli and calculated dissociation energy per unit volume. An excellent agreement between the theoretical and experimental elastic moduli was achieved for majority of the samples. The correlation between bulk modulus and the ratio between packing density and mean atomic volume has also been achieved on the basis of Abd El-Moneim and Alfifi’s approaches.

Elastic Properties of Vanadium Doped Silica-Borotellurite Glasses

2020 ◽  
Vol 307 ◽  
pp. 321-326
Author(s):  
Nurhayati Mohd Nor ◽  
Halimah Mohamed Kamari ◽  
Amirah Abdul Latif ◽  
Nurisya Mohd Shah
Keyword(s):  
Elastic Properties ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Molar Fraction ◽  
Glass Network ◽  
Ultrasonic Pulse ◽  
Ultrasonic Velocities ◽  
Wave Velocities ◽  
Network Glass ◽  
Pulse Echo

Silica borotellurite glasses doped with different molar fraction of V2O5 have been prepared by melt quenching technique. The elastic properties of {[(TeO2)0.7 (B2O3)0.3]0.8(SiO2)0.2}(1-x)(V2O5)x glasses are investigated using ultrasonic pulse echo measurements and their elastic properties have been characterized at room temperature. The density of the glasses was measured by Archimedes method using distilled water as buoyant liquid. The ultrasonic wave velocities (longitudinal, vl and shear, vS) were recorded at 5 MHz. Elastic moduli, Poisson’s ratio (σ) and microhardness (H) were then calculated to obtain quantitative analysis regarding the structure of these glasses. The results obtained showed that the doping of V2O5 with silica borotellurite enhances the strengthening of glass network. Glass with 0.03 molar fraction of V205 shows low ultrasonic velocities and low elastic moduli. The variation of elastic properties is related to the change of structure in the vanadium doped silica-borotellurite glass system.

Changes in tobacco depictions after implementation of tobacco-free film and TV rules in Bollywood films in India: a trend analysis

2021 ◽  
pp. tobaccocontrol-2021-056629
Author(s):  
Gaurang P Nazar ◽  
Monika Arora ◽  
Nitika Sharma ◽  
Surbhi Shrivastava ◽  
Tina Rawal ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Trend Analysis ◽  
Poisson Regression ◽  
Poisson Regression Analysis ◽  
Free Film ◽  
Rule Compliance ◽  
Increasing Trend ◽  
Before And After ◽  
Year 2013

BackgroundIndia’s tobacco-free film and TV rules were implemented from 2012. To assess the effect of the rules, we studied tobacco depictions in top-grossing Bollywood films released between 2006 and 2017 and rule compliance after 2012.MethodsTobacco incidents and brand appearances were coded in 240 top-grossing Bollywood films (2006–2017) using the Breathe California method. Trends in number of tobacco incidents per film per year were studied before and after implementation of the rules using Poisson regression analysis. Compliance with rules over the years was studied using Pearson product-moment correlations.ResultsForty-five films were U-rated (all ages), 162 were UA-rated (below age 12 years must be adult-accompanied), and 33 were A-rated (age 18+ years only). Before implementation of the rules, the number of tobacco incidents per film was increasing by a factor of 1.1/year (95% CI 1.0 to 1.2, p=0.002). However, beginning year 2013, the number of incidents per film started falling significantly by a factor of 0.7/year (95% CI 0.6 to 0.9; p=0.012) compared with the previous increasing trend. The percentage of youth-rated (U and UA) films with any tobacco incidents also declined from a peak of 76% in 2012 to 35% in 2017. The percentage of films complying with the rules (audio-visual disclaimers, health spots, static warnings) did not change significantly from 2012 to 2017.ConclusionIndia’s 2012 rules were followed by a reduction in tobacco depictions in Bollywood films. Enhanced monitoring of compliance is needed to ensure the continued effectiveness of the rules.

scholarly journals Elasto-mammography: Theory, Algorithm, and Phantom Study

2006 ◽  
Vol 2006 ◽  
pp. 1-11 ◽  
Author(s):  
Z. G. Wang ◽  
Y. Liu ◽  
L. Z. Sun ◽  
G. Wang ◽  
L. L. Fajardo
Keyword(s):  
Elastic Moduli ◽  
Imaging Modality ◽  
Contrast Ratio ◽  
Reconstruction Algorithm ◽  
Displacement Measurement ◽  
Breast Compression ◽  
Before And After ◽  
Breast Tissues ◽  
Displacement Information

A new imaging modality framework, called elasto-mammography, is proposed to generate the elastograms of breast tissues based on conventional X-ray mammography. The displacement information is extracted from mammography projections before and after breast compression. Incorporating the displacement measurement, an elastography reconstruction algorithm is specifically developed to estimate the elastic moduli of heterogeneous breast tissues. Case studies with numerical breast phantoms are conducted to demonstrate the capability of the proposed elasto-mammography. Effects of noise with measurement, geometric mismatch, and elastic contrast ratio are evaluated in the numerical simulations. It is shown that the proposed methodology is stable and robust for characterization of the elastic moduli of breast tissues from the projective displacement measurement.

Evaluation of the Bioactivity Behavior of a 48 Wt %SiO2 Bioglass through Experiments in Simulated Body Fluid

2012 ◽  
Vol 727-728 ◽  
pp. 1238-1242 ◽  
Author(s):  
Roger Borges ◽  
Antônio Carlos da Silva ◽  
Juliana Marchi
Keyword(s):  
Corrosion Resistance ◽  
Surface Layer ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Glass Network ◽  
In Vitro Experiments ◽  
High Corrosion Resistance ◽  
Before And After ◽  
O 19

Among bioceramics materials, bioglasses which exhibits either a bioactive or resorbable behavior has been studied for many applications, such as bone substitutive and regeneration. When in contact with body fluid, the bioglasses can induce the formation of a hydroxyapatite surface layer. In this paper, we studied the bioactivity of a bioglass containing 48 wt %SiO2, 27 wt% Na2O, 19 wt % CaO and 6 wt %P2O5. After fusion and annealing, the samples were immersed in SBF for different periods, up to 14 days. The samples were characterized through XRD, DRIFT and SEM before and after bioactivity experiments. The overall results suggest the formation of a surface layer of consisting of hydroxyapatite, which was crystallized within seven days after in vitro experiments, leading to a suitable bioactivity. Moreover, the samples showed a glass network with high cohesion due to calcium addition, leading to materials with high corrosion resistance.

scholarly journals Effect of Gamma Radiation on Characteristic of bipolar junction Transistors (BJTs )

2021 ◽  
pp. 1-9
Author(s):  
Abdenabi Ali Elamin ◽  
Waell H Alawad
Keyword(s):  
Gamma Radiation ◽  
Power Supplies ◽  
Strong Increase ◽  
Bipolar Junction Transistors ◽  
Bipolar Junction Transistor ◽  
Before And After ◽  
Junction Transistor ◽  
The Individual ◽  
Silicon Transistor ◽  
Different Doses

This paper describes the effects of 60Cogamma radiation hardness of characteristic and parameters of Bipolar Junction Transistors in order to analyze the performance changes of the individual devices used in nuclear field. Bipolar Junction Transistor (BJT) of the type (BC-301) (npn) silicon, Transistor was irradiated by gamma radiation using 60Cosource at different doses (1, 2, 3, 4, and 5) KGy. The characteristics and parameter of Bipolar Junction Transistor was studied before and after irradiated by using Transistor Characteristics Apparatus with regulated power supplies. Obtained result showed that, the saturation voltage VCE(sat) of Bipolar Junction Transistor decreased because of the gain degradation of the transistor and increased silicon resistivity, Another parameter of a bipolar junction transistor affected by ionizing radiation is a collector-base leakage current, a strong increase of the current is caused by the build-up charge near the junction.

scholarly journals Roles of Climate Variability on the Rapid Increase of Winter Haze Pollution in North China after 2010

2020 ◽  
Author(s):  
Yijia Zhang ◽  
Zhicong Yin ◽  
Huijun Wang
Keyword(s):  
North China ◽  
Economic Losses ◽  
Early Winter ◽  
Premature Deaths ◽  
The Pacific ◽  
Haze Pollution ◽  
Increasing Trend ◽  
Before And After ◽  
Increasing Trends ◽  
Trend Reversal

Abstract. North China experiences severe haze pollution in early winter, resulting in many premature deaths and considerable economic losses. The number of haze days in early winter in North China (HDNC) increased rapidly after 2010 but declined slowly before 2010, reflecting a trend reversal. Global warming and emissions were two fundamental drivers of the long-term increasing trend of haze, but no studies have focused on this trend reversal. The autumn SST in the Pacific and Atlantic, Eurasian snow cover and central Siberian soil moisture, which exhibited completely opposite trends before and after 2010, were proven to stimulate identical trends of meteorological conditions related to haze pollution in North China. Numerical experiments with a fixed emission level confirmed the physical relationships between the climate drivers and HDNC during both decreasing and increasing periods. These external drivers induced a larger decreasing trend of HDNC than the observations, and combined with the persistently increasing trend of anthropogenic emissions, resulted in a realistic slowly decreasing trend. However, after 2010, the increasing trends driven by these climate divers and human emissions jointly led to a rapid increase in HDNC.

Preparation and Performance Study of Fluorosilicone Oligomer Anti-Sticking Coatings

2020 ◽  
Vol 841 ◽  
pp. 209-213
Author(s):  
Dong Bo Guan ◽  
Xiao Jie Zhai ◽  
Ying Nan Biansai ◽  
Bo Jun Cao ◽  
Yong Fu Zhu ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Contact Angle ◽  
Infrared Spectroscopy ◽  
Contact Time ◽  
Curing Agent ◽  
Performance Study ◽  
Film Forming ◽  
Increasing Trend ◽  
Before And After ◽  
And Performance

In this paper, fluorosilicone oligomer and its curing agent are used as the main film-forming materials, and fluorosilicone POSS is added to reduce the surface energy of the composites to prepare a coating with certain anti-sticking effect. The changes of molecular structure before and after the reaction were obtained by infrared spectroscopy. The contact angle and anti-sticking property of the coating surface were studied by changing the content of POSS containing fluorine. It was found that the contact angle of fluorine-containing POSS reached 98.7° when the content of fluorine-containing POSS was 3 Wt.%. With the increase of POSS content, the anti-sticking force of composites changed little, but with the increase of the contact time of tape, the anti-sticking force showed an increasing trend.

Elastic properties and phonon conductivities of Ti3Al(C0.5,N0.5)2 and Ti2Al(C0.5,N0.5) solid solutions

2008 ◽  
Vol 23 (6) ◽  
pp. 1517-1521 ◽  
Author(s):  
M. Radovic ◽  
A. Ganguly ◽  
M.W. Barsoum
Keyword(s):  
Elastic Properties ◽  
Solid Solutions ◽  
Room Temperature ◽  
Elastic Moduli ◽  
Unit Cell ◽  
Young’S Moduli ◽  
Temperature Shear ◽  
End Members ◽  
Cell Volumes ◽  
Thermal Conductivities

Herein we compare the lattice parameters, room temperature shear and Young’s moduli, and phonon thermal conductivities of Ti2AlC0.5N0.5 and Ti3Al(C0.5, N0.5)2 solid solutions with those of their end members, namely Ti2AlC, Ti2AlN, Ti3AlC2, and Ti4AlN2.9. In general, the replacement of C by N decreases the unit cell volumes and increases the elastic moduli and phonon thermal conductivities. The increase in the latter two properties, however, is sensitive to the concentrations of defects, most likely vacancies on one or more of the sublattices.

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