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Structural and In-Vitro Characterization of Bioactive Glass Ceramics With Different Cao/Mgo Ratios

Thesis Info

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Author

Hashmi, Muhammad Usman

Program

PhD

Institute

Government College University

City

Lahore

Province

Punjab

Country

Pakistan

Thesis Completing Year

2004

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1975

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727244422

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Bioceramics and bioglass ceramics are a wide arena of research in the current era due to their potential applications in orthopedics and surgery. In the present work, Glasses of novel composition (50-x) CaO – 34 SiO 2 -14.5 P 2 O 5 -1 CaF 2 -0.5 MgF –x MgO (% wt) (where x=4, 25 and 46) were synthesized by conventional melt-quench method. Each glass was sintered at different temperatures according to the endothermic and exothermic peaks of differential scanning calorimetric (DSC) data to form three glass ceramics named G1, G2 and G3 respectively. Crystalline phases of hydroxyapatite and wollastonite were observed in G1 and G2 whereas new phase of whitlockite was observed in G3 by X-Ray diffractometer (XRD) due to greater amount of MgO. Bulk properties of the samples were examined by studying density using Archimedes principle. Morphological study by scanning electron microscope (SEM) illustrated that the rate of densification increased with the decrease of CaO/MgO ratio. Bulk properties of the samples and morphological study by SEM revealed that rate of densification increased with the decrease of CaO/MgO ratio. Micro-hardness values (5192-6467 MPa) and bending strengths (211- 281 MPa ) were found to be increased with increase of MgO in the composition and the results were in accordance to that of XRD, SEM and bulk density. After investigating the structural and mechanical properties of the samples, in- vitro dissolution behavior of the same samples was investigated in conventional simulated body fluid (Kokubo’s SBF-K9). Ionic concentration of SBF-K9 slightly varies from that of human blood plasma (less CO 3- ions and high Cl - ion). So it could be presumed that it could show slightly different results in-vivo. In order to avoid this situation and to clearly understand the behavior of G1, G2 and G3 in the in-vivo environment, bioactivity of the samples was further investigated in revised SBF (r-SBF) that has ionic concentration exactly equal to that of human blood plasma (HBP) and a comparative study of dissolution behavior of the samples, in SBF-K9 and r-SBF was performed. For that purpose, first, the stability of r-SBF and SBF-K9 was checked by observing the spontaneous precipitations on the surfaces of solutions, using atomic absorption spectroscopy and measuring the pH values, after respective days. Due to thexii loss of stability of r-SBF after 25 days, we investigated the dissolution behavior of each sample in each solution upto 25 days. To perform the comparative study, thin film X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscope (SEM), Energy dispersive spectroscopy (EDX), Atomic absorption spectroscopy (AAS) and pH meter were used. Thin film XRD analysis revealed the diffusive nature of the phases on the surfaces of samples after soaking for different time periods in r-SBF. It showed the poor precipitation and small thickness of the HCAp layer on the samples as compared to that in SBF-K9, thus indicating the fitness and sensitivity of r-SBF for in-vitro characterization of samples. AAS, FTIR and EDS revealed slow bonding rate on the surfaces of the samples in r-SBF than that in SBF-K9 that showed the dependence of bond formation on the composition of the materials as well as on the physiological fluid used for in-vitro characterization. The rate of HCAp formation was slower in r-SBF due to more competitive adsorption of CO 3- ions to Ca and Mg ions owing to greater amount of CO 3- in r-SBF than that in SBF-K9. It shows the importance of CO 3- content in the physiological fluids for the in-vitro assessment of samples. Due to equal ionic concentration of HBP and r-SBF, assessment of samples in r-SBF could clearly indicate the exact timing of bond formation and behavior of samples in-vivo. So, r-SBF is recommended to be used for assessment of samples to clearly understand their behavior in-vivo.
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خود شناسی خدا شناسی ہے

خودشناسی خدا شناسی ہے
اللہ تعالیٰ نے ہر چیز جو پیدا فرمائی ہے اس کی ایک شناخت ہے، سورج کی ا یک شناخت ہے کہ وہ مشرق سے طلوع ہوتا ہے اور مغرب میں غروب ہوتا ہے۔ ستارے رات کو چمک کر شب دیجور کے لیے ضیاکا سامان بہم پہنچاتے ہیں اور مسافرانِ شب کے لیے خضر راہ بنتے ہیں تو یہ ستاروں کی ایک شناخت ہے، فلک بوس پہاڑ اور جبال شامخہ کا ایک طویل سلسلہ بھی اپنی شناخت رکھتا ہے۔ الغرض دنیا و مافیہا ہر چیز اپنی شناخت رکھتی ہے۔ جس کے باعث اس کا وجود قائم ہے۔
انسان کی بھی ایک شناخت ہے کہ وہ حیوان ناطق ہے اور ذوی العقول ہے، اس کی چال ڈھال، اس کی نشست و برخاست، اس کا قیام وقعود، اس کی گفت وشنید اس کو دیگر مخلوقات سے ممتاز کرتی ہے، اور پھر قرآن پاک اس کو اشرف المخلوقات کا لقب عطا فرما کر انسانیت کی معراج پرمتمکن بنادیتا ہے، اس سے بڑھ کر مسلمان جو اسلام کے زیور سے مرصعّ ہے، جس نے دینِ اسلام کا تاج اپنے سر پر سجایا ہوا ہے، جس نے عشق مصطفی صلی اللہ علیہ و آلہٖ وسلم کی خلعت ِفاخرہ زیب تن کی ہوئی ہے اس کی بھی ایک شناخت ہے، اور وہ یہ کہ ارشادِ رسالت مآب صلی اللہ علیہ و آلہٖ وسلم ہے ’’مسلمان وہ ہے جس کے ہاتھ اور زبان سے دوسرے مسلمان محفوظ رہیں‘‘ یعنی اسلام کے دعویدار تو بے شمار ہیں لیکن دینِ اسلام کے احکام پر عمل پیرا حقیقت میں وہی ہے جو مذکورہ حدیث پاک کے مطابق اپنی شناخت رکھتا ہے۔
کرسی عدالت پر بیٹھ کر فیصلہ سنانے والے منصف کی ایک شناخت ہے۔ شفاخانوں میں موجود مریضوں کے علاج کرنے والا مسیحا کی ایک شناخت ہے، سرحدوں پر مامور محافظ مجاہد کی ایک...

استنباط احکام میں حضرت عائشہ کا منہج قرآن کریم کی روشنی میں

In this article an effort has been made to describe Hazrat ‘฀ishah (R. A) ’s methodology of derivation of Ahk฀m from Holy Quran. Holy Quran and Sunnah of Holy Prophet (S. A. W) is basic source of Islamic Shar฀‘ah. Hazrat ‘฀ishah Sidd฀qah (R. A) was the wife of the Holy Prophet (S. A. W), and the daughter of Hazrat Ab฀ Bakr (R. A). She spent her time in learning and acquiring knowledge of the two most important sources of Islam, the Qur'an and the Sunnah of His Prophet (S. A. W). Hazrat ‘฀ishah (R. A) narrated 2210 Ah฀d฀th out of which 174 Ah฀d฀th are commonly agreed upon by Bukh฀ri and Muslim. She was an ardent and zealous student of Islamic jurisprudence. She has not only described Ah฀d฀th and reported her observations of events, but interpreted them for derivation of Ahk฀m. Umm Al-Mu’min฀n Hazrat ‘฀ishah (R. A) is a great scholar and interpreter of Islam, providing guidance to even the greatest of the Companions (R. A) of the Holy Prophet Muhammad (S. A. W). She has not only described Ah฀d฀th and reported her observations of events, but interpreted them for derivation of Ahk฀m. Whenever necessary, she corrected the views of the greatest of the Companions of the Holy Prophet (S. A. W). It is thus recognized, from the earliest times in Islam, that about one-fourth of Islamic Shar฀‘ah is based on reports and interpretations that have come from Hazrat ‘฀ishah (R. A). As a teacher she had a clear and persuasive manner of speech. Hazrat ‘฀ishah (R. A) is a role model for women. She taught Islam many people. She was an authority on many matters of Islamic Law, especially those concerning women.

Gamma-Operations in Topological Spaces

In 1997, S. Kasahara [51] defined an operation α on Topological Spaces and introduced the concept of an α-closed graph of a function. In 1983, D. S. Jankovic [48] defined α-closed set and further investigated functions with α-closed graphs. In 1992, F. U. Rehman and B.Ahmad [91] introduced the notions of γ-interior, γ- boundary and γ-exterior points in the Topological Spaces and studied their properties. They studied properties and characterizations of (γ,β)-continuous mappings introduced by H. Ogata [88]. They also studied some interesting characterizations of (γ,β)-closed (open) mappings in Topological Spaces. In [41], S. Hussain investigated the basic properties of γ-operations in Topological Spaces by introducing γ-limit point, γ-derived set, γ-dense in itself, γ-nbd. and γ-nbd. system. H. Ogata [88], introduced the notions of γ-Ti spaces, for i=0, 1/2, 1, 2 and studied their properties. The properties of (γ,β)-continuous functions have also been studied in General Topological Spaces as well as in γ-T2 spaces. The concept of γ-convergence of a sequence, and its properties have been defined and investigated in γ-T2 spaces. Concepts like γ*-regular space in Topological Spaces have also been defined and their properties in γ-T2 space have been explored in [8]. The study of semi-open sets and their properties was initiated by N. Levine [63] in 1963. The introduction of semi-open sets raised many basic General Topological questions, which has thus far led to a productive study in which many new mathematical tools have been added to the General Topology tool box. Many new notions have been defined and examined. Many new properties and characteristics of classical notions have been studied. The purpose of this thesis is to study these notions in terms of γ-operations in Topological Spaces We divide the work into seven chapters. In 1975, Maheshwari and Prasad [67], have defined new axiom called s- regularity, which is strictly weaker than regularity (without T2). In 1982, C. Dorsett [30], defined and investigated a separation axiom called semi-regular space. It is shown [30] that s-regularity is weaker than semi-regularity. A new class of regularity called s*-regular spaces, PΣ and weakly PΣ spaces, locally s-regular space, P-regular space and γ*-regular space have been defined and studied in [19], [52], [59] and [8]. In chapter 1, we discuss the characterizations and properties of γ- convergence, γ*-regular, γ0-compact, γ-locally compact and γ-normal spaces. In section 2, we investigate the characterizations of γ-convergence, γ*-regular spaces defined in [8]. In section 3, we define and discuss the γ0-compact space, which is the generalization of compact space, and study the properties of γ0-compact space in (γ,β)-continuity defined and investigated by H. Ogata [88] and further studied by F. U. Rehman and B. Ahmad [91]. Several properties and characterizations of γ0- compact space have been explored in this section. In section 4, we define and investigate γ-locally compact space in General Topological Space as well as in γ-T2 space [88]. It is interesting to mention that every γ0-compact space is a γ-locally compact space. In section 5, we define γ-normal space which is independent of normal space. We study its properties and characterizations in γ-T1 spaces under (γ,β)- continuous functions defined in [88]. In chapter 2, we define a new space called γ-connected space. It is remarkable that the class of connected spaces is the subclass of class of γ-connected spaces. In section 2, we study the characterizations and properties of γ-connected spaces and then properties under (γ,β)-continuous functions [88]. In section 3, we define and explore the characterizations of γ-components in a space X. In section 4, we define and discuss a new notion called γ-locally connected space which generalizes locally connected space. In section 5 and 6, we define and investigate γs-regular and γs- normal spaces. Here we also study the relation of γ0-compact, γ-T2 spaces and γs- normal spaces. In chapter 3, we define γs-connected space and γs-locally connected space and analyze their many interesting properties and characterizations. We also define and explore the properties of γs-components in a space X. In 1992 (respt. 1994), J. Umehara, H. Maki and T. Noir (respt. J. Umehara) [97] (respt. [98]) defined and discussed the properties of ( γ,γ ′)-open sets, ( γ,γ ′)- closure, and ( γ,γ ′)-generalized closed sets in a space X. In chapter 4, we continue to discuss the properties of (γ,γ ′)-open sets, (γ,γ ′)-closure, (γ,γ ′)-generalized closed sets [97] which generalizes the γ-open sets, γ-closure and γ-generalized closed sets defined by H. Ogata [88] and further investigated in [91] and [7]. It is interesting to Remark 4.2.9 that the class of (γ,γ ′)-open sets contains the class of γ-open and the class of γ ′- open sets. In section 2, we define and discuss the properties of (γ,γ ′)-interior, (γ,γ ′)- closure and (γ,γ ′)-boundary. In section 3, we define and explore many interesting properties of τ(γ, γ ′ ) - cl (A) and (γ,γ ′)-generalized closed sets [97]. It is necessary to mention that τ(γ, γ ′ ) - cl (A) generalizes τγ - cl (A) defined by H. Ogata [88]. We also examine the relation of τ(γ, γ ′ ) - cl (A), cl(A), clγ(A ) and cl(γ, γ ′) (A) in Theorem 4.3.14 (1). In section 4, we define and explore the properties of (γ,γ ′)-nbd and (γ,γ ′)-nbd base at x which generalizes γ-nbd and γ-nbd base at x defined in [7]. In section 5, we define (γ,γ ′)-T1 space and describe many of their characterizations and properties. We also define and explore (γ,γ ′)-derived sets which generalizes γ-derived sets defined in [7]. In chapter 5, we define a new class of continuous functions called Bi (γ,β)- continuous functions and investigate several properties and characterizations of Bi (γ,β)-continuity and Bi (γ,β)-open (closed) functions. In 1963, Levine [63] defined semi-open sets in a space X and discussed many of its properties. In 1997 (2005), A. Csaszar [25-26] defined Generalized Topological Spaces. In 1975, Maheshwari and Prasad [61] introduced concepts of semi-T1 spaces and semi-R0 spaces. In 2005, A. Guldurdek and O.B. Ozbakir [40] defined and discussed γ-semi-open sets using γ-open sets in Topological Spaces which are different from the notions of γ-open sets introduced and studied by H. Ogata [88] in 1991. So far several researchers worked on the findings of H. Ogata and a lot of material is available in the literature. In sections 2 and 3 of chapter 6, we introduce the concept of γ*-semi-open (which generalizes γ-open sets defined in [88]), γ*-semi- closed sets and γ*-semi-closure, γ*-semi-interior sets in a space X in the sense of H. Ogata [88]. It is also shown that the concept of semi open sets and γ*-semi-open sets are independent of each other. In view of the findings of [40], we also introduce γ Λγs − set and Λs − set by using γ*-semi-open sets. Moreover, we show that the concepts of g. Λ s − set , g. V s − set , semi-T1 space and semi-R0 space can be generalized by replacing semi-open sets with γ*-semi-open sets for an arbitrary monotone operator γ∈Γ(X). In section 4, we discuss the several properties of γ*-semi- open sets by defining and studying γ*-semi-interior, γ*-semi-closure, γ*-semi- boundary and their relations between them. In 1963, Levine [63] defined the notion of semi-continuous function. Since then, this notion has been extensively investigated. Cameron and Woods [23] and Abd El-Monsef et-al [1] have independently defined s-continuous and strongly continuous functions respectively. In 1994, M. Khan and B. Ahmad [55] introduced almost S- continuous functions. They showed that almost S-continuous have certain similar properties to those of strongly θ-continuous functions obtained by Long and Herrington [65]. In section 2 of chapter 7, we introduce and investigate the notion of γ-semi-continuous function. It is shown that γ-semi-continuous functions have certain similar properties to that of semi continuous functions [63]. Although γ-semi- continuous functions and semi continuous functions are independent of each other. In section 3, we define and explore many interesting properties and characterizations of γ-semi-open (closed) functions. In section 4, we define γ*-irresolute functions and discuss the properties and characterizations in terms of γ*-semi-derived sets and γ- semi-T2 space In section 5, we define and study the γ-pre-semi-open (closed) functions in space X. We explore the properties and characterizations of them in terms of γ*-semi-interior, γ*-semi-closure, (γ,β)-continuous, and (γ,β)-open (closed) functions [4], [88], [91]. In the end, we study the relationship between γ-pre-semi- open (closed) functions and γ*-irresolute functions." xml:lang="en_US