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Home > Study of Zinc Ferrite Containing Ferrimagnetic Bioactive Glass Ceramics for the Hyperthermia Treatment of Cancer

Study of Zinc Ferrite Containing Ferrimagnetic Bioactive Glass Ceramics for the Hyperthermia Treatment of Cancer

Thesis Info

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Author

Shah, Saqlain Abbas

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/123456789/1972

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727401851

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Ferrimagnetic bioactive glass ceramics are expected to be potential candidates for the hyperthermia treatment of cancer. When placed in an alternating magnetic field of high frequency, these materials generate heat energy by hysteresis and eddy current losses. Tumor cells usually perish around 43 °C due to the poorly developed nervous and circulatory system whereas healthy body cells remain unaffected at this temperature. Such materials should have the adequate ability to bond with the tissues (bioactivity). Much work has been done on Fe 3 O 4 containing glass ceramics for this purpose but present work is the first ever detailed study of its kind on ZnFe 2 O 4 containing ferrimagnetic bioactive glass ceramics for the hyperthermia treatment of cancer. Glass ceramics of the composition (%wt) xZnO • 25Fe 2 O 3 • (40 -x)SiO 2 • 25CaO • 7P 2 O 5 • 3Na 2 O were prepared by melt-quench method and subsequent sintering at 1100 °C. After sintering the materials were quenched to about -10 °C to cause ferrimagnetism by preserving the high temperature state of mixed spinels, i.e., random distribution of cations at tetrahedral (A) and octahedral (B) sites of the spinel lattice. Magnetic properties of ferrimagnetic materials were further enhanced by cooling the materials in an aligning magnetic field to cause anisotropy. XRD was used to study the crystalline phases in the materials. Magnetic properties of the materials were studied using VSM. The sample X10 (having 10% ZnO) exhibited the highest hysteresis area. Calorimetric properties were studied by placing the materials in a magnetic induction furnace. The sample X10 exhibited the best magnetic heat generation due to its highest hysteresis losses. Anisotropic materials showed better magnetic and calorimetric properties than the non-aligned materials. Materials were immersed in simulated body fluid (SBF) for 3 weeks to study the bioactivity. In Vitro characterization was carried out using XRD, FTIR, SEM, EDS, AAS & pH meter. The results confirmed that all samples were bioactive as layers of biological hydroxycarbonate apatite (HCA) appeared after 3 weeks. Sample X10 exhibited adequate bioactivity. Due to balanced calorimetric & biological properties, sample X10 was considered the potential material of choice to be used for the hyperthermia treatment of cancer as well as for re-enforcement of the damaged bones.
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سانچ کو آنچ نہیں

سانچ کو آنچ نہیں
مالا لکڑ، ٹھاکر پتھر، گنگا جمنا پانی
جب تک دل میں سانچ نہ آوے چاروں وید کہانی
’’ سانچ کو آنچ نہیں‘‘ کا مطلب ہے کہ سچائی میں برکت ہے، سچ بولنے والا خواہ مرد ہو،سچ بولنے والی عورت ہو، سچ بولنے والا بڑا ہو، صداقت اجتماعی صورت میں ہو یا انفرادی طور پر ہو ہمیشہ ایک مسلم معاشرے میں مستحسن گردانی جاتی ہے، سچ بولنے والے افراد معاشرے کے ماتھے کا جھومر ہوتے ہیں۔ سچ سے روگردانی کرنے والے اور کذب بیانی کے عادی افراد ایک صحت مند معاشرے کے قیام میں نہ صرف سدِ سکندری ثابت ہوتے ہیں بلکہ ان کا وجود بے سود اقوام میں ناسور کی شکل میںمتشکل ہوتا ہے۔
اللہ تعالیٰ نے اپنی کتاب لاریب میں ارشاد فرمایا ہے کہ ’’اے ایمان والو! اللہ سے ڈرو اور سچوں( صادقین) کے ساتھ ہو جاؤ‘‘ ، اس سے یہ بات مترشحّ ہورہی ہے کہ صداقت اور سچائی ایک ایسی عظیم صفت ہے جس سے متصف مقدس ہستیوں کی معیت کا حکم جوخودخدائے لم یزل دے رہا ہے۔
جن کے سر پر سایۂ صِدق و صفا ہو جائے گا
راشدؔ راضی آپ ہی ان سے خدا ہو جائے گا
اوراق تاریخ کی ورق گردانی کریں تو یہ بات روز روشن کی طرح عیاں ہے کہ جن لوگوں نے صداقت اور سچائی کا دامن تھامے رکھا وہ میدان ِراست بازی کے شاہسوار بنے۔ دروغ گو،ملعونین اور کاذبین، صادقین کے گھوڑے کے سُموں سے اڑنے والی دھول کو بھی نہ پہنچ سکے، سینے پر صداقت کا تمغہ اور سر پر راست بازی کا تاج رکھنے والے افراد ہی آسمانِ علم و دانش پر آفتاب نصف النہار کی طرح چمکتے ہیں۔
صداقت ایک ایسا وصف ہے کہ جس نے اس زیور سے اپنے آپ کو مزیّن و مرصعّ کیا دین ودنیا میں کامیاب و...

The Musharraf Formula (Back Channel Formula) and the Resolution of the Kashmir Conflict

The Musharraf formula refers to the resolution formula of the Kashmir conflict which was reportedly agreed upon during the one-to-one backchannel dialogue between Mr. Tariq Aziz, the former civil servant and close aide of the then President of Pakistan, General Pervez Musharraf and Mr. Satinder Lambah, a special envoy of the Prime Minister of India. We now know some of the details of this formula from the article of the American journalist, Steve Coll which he had published in New Yorker in March 2009 and the book of Mr. Khursheed Mahmud Kasuri, Neither a Hawk, Now a Dove which was published in 2015. Prior to this Mr. Musharraf and Mr. Kasuri had already claimed in their TV interviews and press talks that by March 2007 India and Pakistan were very close to resolving the Kashmir conflict. This paper takes the details of that non-paper agreement and tries to study what exactly that agreement holds for the future resolution of the Kashmir conflict. The basic understanding is whenever the Pakistani and the Indian governments will take up the negotiations on the Kashmir conflict in future, this agreement is bound to come up in the talks as a starting reference point. Therefore, it is necessary to carefully look at this agreement and discuss what it entails for the resolution of the Kashmir conflict.

Seismicity of Pakistan and Formulation of Attenuation Relationship

This study is two pronged. Firstly, it analyses the recorded seismic data in order to ascertain the nature of seismogenic sources. Secondly, it focuses on the development of an empirical attenuation relationship for the study area (northern part of Pakistan). The analysis of seismic data demonstrates that the area has substantial potential to generate frequently low to moderate seismicity originating from relatively shallow crustal depth. The magnitude (ML) of the major earthquakes included in this study ranged 5.0-7.0. The Kohat (ML= 6.0), Astor Valley (ML= 6.2) and Kaghan Valley (ML= 5.6) earthquakes collectively inflicted around 100 fatalities, left 250 people injured and made around 2000 people homeless. However, Fatehjang (ML= 5.3) and Mangla (ML= 5.0) earthquakes caused no human casualty. Focal mechanism solutions of the Kaghan Valley and Kohat earthquakes suggested that the earthquakes were predominantly due to thrust faults, striking NNW-SSE and E-W, dipping 510 and 200 towards NE and N respectively, with minor strike slip component. The solutions agreed well with the nature of seismogenic sources. Similarly, fault plane solution indicated that Mangla earthquake was also owing to thrust, striking E-W and gently dipping towards N. In contrary, focal mechanism solutions for Astor Valley and Fatehjang earthquakes demonstrated that these earthquakes were caused by normal thrust faults, striking NE-SW and NNW-SSE, dipping 620 and 510 towards NW and NE, respectively. The solutions did not match with the nature of the faults causing these earthquakes. However, more seismic data are required to find a plausible explanation of that mismatch. The intensity maps of these earthquakes indicated intensity (MMI) in the range of V-VIII. The Muzaffarabad earthquake of magnitude (ML) 7.0 was however extremely devastating. Death toll was around 75000, injured people were 100,000 and around four million were displaced. Post earthquake seismicity included 6330 earthquakes within first month, 296 of which had magnitude (ML) greater than 4.0. Aftershocks were distributed over a length of 120 Km and were mostly concentrated in the northern extent of the Kashmir Thrust. Focal mechanism solutions demonstrated that Muffarabad earthquake was predominantly due to thrust, striking NNW-SSE and steeply dipping NE, with minor strike slip component. The solutions coincided well with slip nature of Kashmir Thrust. The intensity map showed remarkably high intensity up to XI. An attenuation relationship was developed for the study area. A comparison of peak ground acceleration (PGA) values assimilated by using newly developed relationship and observed PGA values for earthquakes of 7.6, 6.4 and 5.0 magnitude showed a good agreement between the observed and assimilated PGA values. However, new relationship slightly overestimated the near field PGA values for earthquakes of magnitude 7.6. This discrepancy may be due to the possible site nonlinearity effects and dearth of near field high quality strong motion data, especially pertaining to earthquakes of greater magnitude. Likewise, a comparison of PGA values predicted by the new relationship and other relationships with observed PGA values for earthquakes of 7.6, 6.4 and 5.0 magnitude demonstrated better fit between the observed PGA values and values assimilated by the new relationship. This suggested the viability of newly developed attenuation relationship to predict peak ground acceleration for earthquakes of wider range magnitude and longer source to seismic station distances.