A Comparative Study of Molecular Motion Cooperativity in Polymeric and Metallic Glass-Forming Liquids

2016 ◽  
Vol 879 ◽  
pp. 151-156 ◽  
Author(s):  
Masaru Aniya ◽  
Masahiro Ikeda ◽  
Sahara
Keyword(s):  
Metallic Glass ◽  
Bond Strength ◽  
Comparative Study ◽  
Coordination Number ◽  
Molecular Motion ◽  
Fragility Index ◽  
Glass Forming ◽  
Cooperative Relaxation ◽  
The Difference ◽  
The Relationship

In order to investigate the relationship between the bonding nature and the cooperative relaxation, a comparative study of the relaxation behavior in polymeric and metallic glass forming systems has been performed based on the Bond Strength–Coordination Number Fluctuation (BSCNF) model developed by the authors. In the present work, we studied the correlations between the fragility m, the Vogel temperature T0, the degree of molecular cooperativity NB, and the Kohlrausch exponent βKWW. The results show that T0 and NB increase, whereas βKWW decreases systematically with the increase of m. Reflecting the difference of the interatomic interactions of the materials considered, the analysis by the present study reveals that the value of NB in ion-conducing polymers is about 5 times larger than that in metallic systems, and for each system, the material dependence of βKWW is clearly seen in the fragility index m and the cooperativity NB.

Fractional Exponent of the Modified Stokes-Einstein Relation in the Metallic Glass-Forming Melt Pd43Cu27Ni10P20

2010 ◽  
Vol 146-147 ◽  
pp. 1463-1468
Author(s):  
Masahiro Ikeda ◽  
Masaru Aniya
Keyword(s):  
Diffusion Coefficient ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Metallic Glass ◽  
Bond Strength ◽  
Coordination Number ◽  
Einstein Relation ◽  
Glass Forming ◽  
Highly Correlated

The diffusion coefficient in the metallic glass-forming systems such as Pd-Cu-Ni-P exhibits a marked deviation from the Stokes-Einstein (SE) relation in the proximity of the glass transition temperature. Such a deviation is characterized by the fractional exponent p of the modified SE expression. For the material Pd43Cu27Ni10P20, it has been reported that it takes the value p = 0.75. In this work, it is shown that the value of p is highly correlated with the ratio ED / ENB, where ED and ENB are the activation energies for diffusion coefficient D and cooperativity NB defined by the Bond Strength-Coordination Number Fluctuation (BSCNF) model. The present paper reports that for the metallic glass-forming melt Pd43Cu27Ni10P20, the fractional exponent p can be calculated accurately within the framework of the BSCNF model.

Analysis of Cooperativity in Metallic Glass Forming Liquids

2014 ◽  
Vol 783-786 ◽  
pp. 1889-1894 ◽  
Author(s):  
Masaru Aniya ◽  
Masahiro Ikeda
Keyword(s):  
Metallic Glass ◽  
Bond Strength ◽  
Temperature Dependence ◽  
Coordination Number ◽  
Atomic Motion ◽  
Structural Units ◽  
Mean Values ◽  
Glass Forming ◽  
The Mean ◽  
Fluctuation Model

The relation between fragility and cooperativity of atomic motion in bulk metallic glass forming liquids is studied based on the bond strength-coordination number fluctuation model. The model describes the temperature dependence of the viscosity in terms of the mean values of the bond strength, coordination number and their fluctuations of the structural units that form the melt. According to the model, the cooperativity increases with the increase of fragility. The model estimates that the magnitude of the cooperativityNBextends approximately from 7 to 60 structural units, depending on the material. The temperature dependence ofNBfor different metallic glass forming systems reveals thatNBincreases with the decrease of temperature. The relation betweenNBand diffusivity of atoms is discussed briefly.

Viscosity of Metallic Glass Forming Liquids: Analysis Based on Bond Strength-Coordination Number Fluctuations

2010 ◽  
Vol 638-642 ◽  
pp. 1621-1626 ◽  
Author(s):  
Masaru Aniya ◽  
Masahiro Ikeda
Keyword(s):  
Metallic Glass ◽  
Bond Strength ◽  
Viscous Flow ◽  
Coordination Number ◽  
Structural Units ◽  
Mean Values ◽  
Glass Forming ◽  
The Mean

A model that describes the viscous behavior in terms of the mean values of the bond strength, the coordination number, and their fluctuations of the structural units that form the melt has been proposed by one of the authors. In the present study, the viscous behavior of several metallic glass forming systems are analyzed by using the model. From the analysis, microscopic information such as the number of bonds that must be broken to observe the viscous flow is obtained. It is also shown that when the magnitudes of energy and coordination number fluctuations are equal, the behavior of the viscosity described by our model corresponds perfectly to the behavior described by the Vogel-Fulcher-Tammann (VFT) equation.

Evaluation of a Characteristic Temperature in the Relaxation of Metallic Glass Forming Liquids

2018 ◽  
Vol 941 ◽  
pp. 2331-2336 ◽  
Author(s):  
Masaru Aniya ◽  
Masahiro Ikeda
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Metallic Glass ◽  
Bond Strength ◽  
Temperature Dependence ◽  
Coordination Number ◽  
Structural Relaxation ◽  
Characteristic Temperature ◽  
Glass Forming ◽  
Metallic Liquids

The high-temperature viscosity of metallic glass-forming liquids is investigated by using the Bond Strength-Coordination Number Fluctuation (BSCNF) model developed by the authors. For many glass-forming liquids, a salient change in the structural relaxation is observed above the melting point. The temperature dependence of the structural relaxation exhibits a deviation from an Arrhenius-like behavior, and upon cooling it transforms to a non-Arrhenius-like one. In the present study, we show that the BSCNF model describes well the high-temperature viscosity behaviors of metallic liquids. The analysis based on the BSCNF model also enables to extract a characteristic temperature at high temperature. The results of the present study show that such characteristic temperature can be a good indicator for the evaluation of the range of the transition from the Arrhenius-like to the non-Arrhenius-like relaxation behavior.

A Comparative Study of the Reproductive Cycles of the Cockles Cerastoderma Edule and C. Glaucum

1971 ◽  
Vol 51 (3) ◽  
pp. 605-622 ◽  
Author(s):  
C. R. Boyden
Keyword(s):  
Comparative Study ◽  
Mixed Population ◽  
Reproductive Maturity ◽  
Cerastoderma Edule ◽  
Shore Level ◽  
The Difference ◽  
Reproductive Cycles ◽  
The Relationship ◽  
Gonad Condition

The reproductive cycles of the two cockles Cerastoderma edule (L.) and C.glaucum (Poiret) (= Cardium lamarcki Reeve) from a mixed population in the Crouch estuary, Essex, have been investigated. Reproductive maturity was estimated by assessment of gonad condition. A difference in maturity related to shore level was noted. The reproductive cycles of the two cockles were found to be essentially similar. Rapid gametogenesis occurred in both cockles in spring, C. edule then spawned in May, whereas C. glaucum did not spawn until July. The difference in time of spawning appears to be responsible for the maintenance of the two genotypes in a sympatric association, as hybridization experiments showed an absence of isolation at the gamete level. The relationship between C. edule and C. glaucum is discussed.

scholarly journals The Social System of the Family in the Islamic Educational Perspective: Comparative Study: النظام الاجتماعي للأسرة في المنظور التربوي الإسلامي: دراسة مقارنة

2021 ◽  
Vol 5 (14) ◽  
pp. 22-1
Author(s):  
Farouq Abdel Kareem Al-Jarrah Farouq Abdel Kareem Al-Jarrah
Keyword(s):  
Comparative Study ◽  
Social System ◽  
Legal Contract ◽  
The Social ◽  
The Family ◽  
Educational Perspective ◽  
The Difference ◽  
International Conventions ◽  
Relationship Of ◽  
The Relationship

The study aimed to reveal the social system of the family, In the Islamic educational perspective, and the researcher used the analytical inductive approach, in his study of texts and opinions, and the deductive approach to extract the concepts and principles of the family's social system, and it consisted of the following investigations: The first topic: the family, its concept and its position, and the second topic addressed: principles The social system of the family related to the marital relationship is a comparative study with the structural functional, and as for the third topic: the principles of the social system of the family in the relationship of fathers with children, the study reached several results, the most important of which are: that the family idiomatically: the social entity consisting of a man and a woman linked by the marital bond, according to The law of God Almighty, and what results from this bond of children, is governed by the approach of Islam, and that the principle of marriage in the relationship is based on the difference of sex, a man and a woman are bound by a legal contract, and in accordance with the human instinct that God Almighty created, and one of the most important recommendations of the study: Explain what is involved He must bear international conventions and conferences about the dangers of violating the Islamic curriculum, with regard to the family, through specialized research studies.

scholarly journals The relationship between attitudes towards menarche and current attitudes towards menstruation of women: A comparative study

2015 ◽  
Vol 12 (2) ◽  
pp. 1120 ◽  
Author(s):  
Nülüfer Erbil ◽  
Neslihan Felek ◽  
Ebru Karakaşlı
Keyword(s):  
Comparative Study ◽  
Age At Menarche ◽  
Affecting Factors ◽  
Menstrual Cycles ◽  
Adequate Information ◽  
Positive Attitudes ◽  
Study Results ◽  
The Difference ◽  
The Relationship ◽  
Geographical Locations

<p><strong>Purpose:</strong> The study was conducted to determine affecting factors and to investigate relationship  between  attitudes towards menarche and current attitudes towards menstruation of women and to compare characteristics of menarche and menstruation of women who were born and raised in the northeastern and western of Turkey. </p><p><strong>Method and Materials:</strong> This descriptive and comparative study was participated totally 400 volunteer women.<strong> </strong>The data were collected using a questionnaire containing defined closed and open-ended questions.</p><p><strong>Results: </strong>The study results showed that women living in Ordu province than women living in Aydın province expressed positive attitudes toward menarche, and the difference was found significant. Nevertheless, attitudes towards current menstruation were similar in both provinces. When the data of 400 women were evaluated together; women’s attitudes towards menarche were compared with the current attitudes towards menstruation, and the difference was found statistically significant. Although attitudes of the women towards menarche varied according to where they lived, their current attitudes towards menstruation were similar. In addition, depending upon the province, there were statistically significant differences in women’s age at menarche, recollection of menarche, and feelings of shame or happiness at menarche, source and adequacy of information about menstruation, and regularity of their menstrual cycle.  </p><p><strong>Conclusions:</strong> Early menstrual experiences may be related to menstrual experiences later in life and women’s attitudes towards menstruation were not affected by geographical locations. In order to develop positive attitudes towards menarche and a woman’s future years of menstrual cycles, it is very important that accurate and adequate information for young girls be provided before menarche. </p>

Perbedaan PERBEDAAN NILAI LEKOSIT ANTARA KOMPONEN DARAH PACKED RED CELLS (PRC) DAN PACKED RED CELLS LEUCODEPLETED (PRC-LD) DI UTD PMI KOTA SURABAYA TAHUN 2019

2021 ◽  
Vol 9 (2) ◽  
pp. 106-111
Author(s):  
Renata Primasari
Keyword(s):  
Comparative Study ◽  
Red Cells ◽  
Blood Component ◽  
Blood Transfusions ◽  
Blood Components ◽  
European Standard ◽  
The Difference ◽  
The Relationship ◽  
Transfusion Reactions

  Abstract This leukodepleted PRC (PRC-LD) is considered capable of preventing reactions related to blood transfusions because it contains only a small number of leukocytes. The blood component of PRC-LD has also been shown to prevent or reduce transfusion reactions. Leukodepleted is a procedure to reduce the number of leukocytes in the blood or blood components to be transfused to a minimum of <1x106 leukocytes/unit (European standard) or reduce the number of leukocytes >99%. The purpose of this study was to see the difference in leukocyte values ​​in the PRC and PRC-LD components. The method used is analytic, namely research that aims to determine the relationship between variables within the scope of the laboratory. The method used is a comparative study. This study used 30 samples of PRC products and 30 samples of Leucodepleted PRC products at UTD PMI Surabaya City with 450 cc bags. The study was conducted in October - December 2019. The result was that the leukocyte value in the PRC blood component contained blood quality that did not meet the specifications as many as 30 bags (100%) had leukocyte levels >1x106 per bag. Meanwhile, the blood component of PRC-LD contains blood quality that meets the specifications as many as 30 bags (100%), having leukocyte levels <1x106 per bag. Conclusion The quality of PRC Leukodepleted blood component products, the quality of leukocyte levels that meet the specifications, there are 30 blood bags (100%). Keywords: Packed Red Cells Leukodepleted

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