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Home > Synergistic Effect of Zirconia and Impurities on the Properties of Mn-Zn Ferrites Synthesized by Mixed Oxide and Auto Combustion Routes

Synergistic Effect of Zirconia and Impurities on the Properties of Mn-Zn Ferrites Synthesized by Mixed Oxide and Auto Combustion Routes

Thesis Info

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External Link

Author

Waqas, Hassan

Program

PhD

Institute

Pakistan Institute of Engineering and Applied Sciences

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2011

Thesis Completion Status

Completed

Subject

Engineering & allied operations

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1419

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727842832

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Two methods namely, conventional mixed oxide and sol gel auto combustion have been adopted to synthesize Mn-Zn Ferrite powder. In sol gel process, nanosized Mn- Zn Ferrite powder was obtained by starting auto combustion reaction in gel containing metal precursors. In each method, electromagnetic properties (saturation magnetization, Curie temperature, magnetic impedance and loss tangent) have been measured after sintering the green compacts (pellets and toroids). The results revealed that Mn-Zn Ferrite synthesized by sol gel auto combustion process had superior electromagnetic properties than conventional mixed oxide method because of possessing single phase and refined microstructure. Apart from the effect of synthesis routes, the role of zirconia (ZrO 2 ) additive (0.2, 0.4 and 0.6 wt%) along with/without impurities i.e. calcia (CaO) & silica (SiO 2 ) on the electrical and magnetic properties of Mn-Zn Ferrite have also been studied. In conventional mixed oxide method, it has been observed that Z2-series (0.2 wt% ZrO 2 along with/without CaO & SiO 2 ) have better electromagnetic properties than pure and other synthesized compositions (Z4-series and Z6-series). It was mainly due to the fine control of grain growth process during sintering. The same series (Z2-series) have also been synthesized by sol gel auto combustion process. Further improvement in magnetic impedance was observed due to the simultaneous effect of zirconia along with impurities and adopted synthesis route. Among all the synthesized compositions, Mn-Zn Ferrite containing 0.2 wt% ZrO 2 & 0.04 wt% CaO synthesized by sol gel auto combustion process possessed optimum properties at high frequency ( > 500 KHz). The presence of smaller grains having faceted morphology and formation of insulating phase along grain boundaries enabled this composition to operate at high frequency band (i.e. 3 MHz to 20 MHz). The operational frequency band of this composition was further broadened (i.e. 100 KHz to 18 MHz) by improving the sintering conditions. Furthermore, light weight and compact size (washer type) toroid core of this selected composition was prepared and tested in lab scale fabricated linear pulse amplifier circuit. The results showed that synthesized core was able to transmit even weak input signals (50 mV) without any loss. It was good achievement regarding the miniaturization of Mn-Zn Ferrite core transformers to meet the demand of modern switch mode power supply units. Beside this bulk study, highly textured Mn-Zn Ferrite films were also developed on glass substrate by using the target prepared by sol gel auto combustion process. Pulse laser deposition technique has been employed to deposit these films under controlled conditions. Results showed that the strain induced during the deposition process was responsible to attain texture in fabricated films. Because of possessing magnificent magnetic properties, fabricated film had a potential to utilize in memory and spintronic devices.
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پنڈت آنند نرائن ملا

پنڈت آنند نرائن ملا
۱۲؍ جون کو اردو تحریک کے قائد پنڈت آنند نرائن ملا چل بسے، وہ ۱۹۰۱؁ء میں لکھنؤ میں پیدا ہوئے تھے، جہاں ان کے والد پنڈت جگت نرائن ملا چوٹی کے وکیل تھے، آنند نرائن ملا بھی تعلیم سے فارغ ہوکر وکالت کے پیشے سے وابستہ ہوئے، پھر الٰہ آباد ہائی کورٹ کے جج اور سینئر جسٹس ہوئے، ۱۹۶۱؁ء میں ریٹائر ہوئے تو سپریم کورٹ میں وکالت شروع کی، لوک سبھا اور راجیہ سبھا کے ممبر بھی منتخب ہوئے لیکن ان کی اصل وجہ شہرت و امتیاز کا باعث یہ ہے کہ وہ اردو کے ایک بڑے شاعر، نقاد، ادیب، سیکولر، انسان دوست اور گنگا جمنی تہذیب کا نمونہ تھے، اردو کی محبت ان کے رگ و پے میں رچی بسی ہوئی تھی اور وہ اس کے اپنی مادری زبان ہونے پر فخر کرتے تھے اور کہتے تھے کہ ’’میں مذہب چھوڑ سکتا ہوں لیکن مادری زبان نہیں چھوڑ سکتا‘‘۔
ان کا شعر ہے:
آتجھ کو گلے لگا کے مٹتی اردو
اک آخری گیت گا لیں تو چلیں
منظوم تصنیفات کے علاوہ بعض نثری تصنیفات بھی یادگار ہیں نظم وغزل دونوں پر قدرت تھی، روایت کی پاسداری کے باوجود کلام میں فرسودگی نہیں۔ مشاعرہ کے شاعر نہ تھے مگر اس میں شرکت کرتے تھے۔ دارالمصنفین کی گولڈن جبلی کے مشاعرہ کی صدارت کی تھی۔ اب غیر مسلموں میں اردو کے ایسے عالم، دانشور اور اس سے گہرا لگاؤ رکھنے والے عنقا ہورہے ہیں اس اعتبار سے ان کی وفات اردو کا واقعی ناقابل تلافی نقصان ہے۔ (ضیاء الدین اصلاحی، جولائی ۱۹۹۷ء)

 

منھج القرآن الكريم في تربية الشباب المسلم

In the present age, youth occupy an important position and can play a very important role in reforming and improving the world conditions. In Quran several methods are suggested for character building of youth for example following “Uswa-e-Hasna” and by preaching and motivation of youth the fear Allah, the crated in their heard for reforming them. In some cases, the punishment can also reformed of youth. Youth is an important entity of any human society. Particularly in an Islamic society, youth has great significance. Youth is considered as a junction of past, present and future. The role of young generation cannot be neglected in the building of character, changes in circumstances and development of society. Youth should play a positive and effective role against various evils, which are prevalent in human society. What can be the religious social, political, ethical and educational duties of the Muslim? How can they play their role in reformation of society? How can they be bright stars of their country by fulfilling their duties? How can the whole humanity and particularly Islamic Ummah get benefits from their youth? The answers to these questions are central idea and theme of this article, generally in the light of Islam and particularly in the light of seerah-un-nabwiyia. In following lines, it has been tried to impart feelings of high self-esteem in the young generation who have forgotten it. It is an effort to motivate the youth for practical actions.

Female Genital Mutilation and its Medicalizationa Qualitative Study Among Healthcare Professionals and Community Leaders in Kisii County

Background: According to the World Health Organization (WHO), female genital mutilation (FGM) includes all procedures that involve removal of the female genitalia and / or injury to the female genital organs for cultural and / or any other nonmedical reason. The practice poses serious threats to women’s health hence violating their health and rights. FGM, also referred to as genital cutting, is deeply rooted amongst the Abagusii community of Kenya, with 84% of the girls cut as per Kenya Demographic Health Survey report of 2014 and the medicalized form slowly replacing the traditional cut. Overall in Kenya, the medicalized form stands at 14% as at 2014. Although FGM is illegal in Kenya, and the existing strategies by government through various laws and policies to curb FGM notwithstanding, its prevalence among the Abagusii community remains unacceptably high and medicalization seems to be increasing. Understanding the experiences and perspectives amongst healthcare professionals and community leaders in this community, will help inform new strategies to curb the practice. Objectives: Primary objective: To explore the experiences and perspectives of health professionals and community leaders towards FGM and its medicalization in Kisii county. Secondary objectives: To establish the experiences and perspectives among health professionals and community leaders on factors that contribute to the continued practice of FGM in Kisii county and secondly, to elicit views of health professionals and community leaders on new strategies that if used, could help curb the medicalization of FGM in Kisii county. Methods: A qualitative study using a focused ethnography approach was conducted to explore the experiences and perspectives of health professionals and community leaders towards FGM and its medicalization in Kisii county. Sampling was purposive. Twenty-six participants (18 health professionals and eight community leaders) from two sub-counties of Kisii County were recruited. Signed informed consent was acquired from all participants. Data collection was done using audio-recorded semi-structured interviews. All audiorecordings were transcribed in English. A thematic approach was used for analysis supported by NVivo version 12 plus software. Results: A total of 18 healthcare professionals (six doctors, six clinical officers, six nurses), eight community leaders (two representatives from local community-based organizations relevant to the study topic of interest, two religious leaders and four chiefs/assistant chiefs) were interviewed. Among health workers, doctors demonstrated more understanding on FGM compared to the other healthcare professionals. All the study participants demonstrated little knowledge on existing laws and policies. The general attitude towards FGM