Search or add a thesis

Advanced Search (Beta)
Home > Synthesis, Electrical Properties and Bio-Compatibility Analysis of Barium Manganate Nanostructures

Synthesis, Electrical Properties and Bio-Compatibility Analysis of Barium Manganate Nanostructures

Thesis Info

Access Option

External Link

Author

Hayat, Khizar

Program

PhD

Institute

Pakistan Institute of Engineering and Applied Sciences

City

Islamabad

Province

Pakistan

Country

Pakistan

Thesis Completing Year

2013

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1755

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676727524284

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Single phase barium manganate nanorods, nanoparticles, nanofibers and microparticles were prepared using composite–hydroxide mediated (CHM) method, hydrothermal (HT) technique, electrospinning (ES) and solid state reaction (SSR) route respectively. Size and uniformity of BaMnO 3 nanorods were optimized against different reaction times and reaction temperatures. BaMnO 3 powders consisting of nanorods of an average diameter ~ 200 nm and length ~1 – 1.5 μm, prepared at reaction temperature 200 °C and reaction time 48 hours, were chosen for electrical characterization. Impedance spectroscopy (IS) from 300 – 400 K and 20 Hz – 2 MHz, revealed presence of non-ideal Debye type behaviour in BaMnO 3 samples and was attributed to the presence of heterogeneity in the sample. The heterogeneity was explained on the basis of “brick layer model”. In BaMnO 3 nanorods sample, on the basis of extracted capacitance values, two electro-active regions were investigated i.e., dominant grain boundaries and sample-electrode interfaces. No indication from the bulk effect was observed. Experimental results were fitted using equivalent circuit model (R gb Q gb )( R e Q e ). The ac and dc conduction mechanisms in BaMnO 3 pellets can be explained by correlated barrier hopping (CBH) model and Poole– Frenkel conduction mechanism respectively. While IS analysis of bulk BaMnO 3 sample revealed that different electro-active regions such as grain, grain boundary and sample- electrode interface exist that overlapped with each other in the applied frequency domain. These results were also modelled via a best fit equivalent circuit model (R g C g )(R gb Q gb )(R e Q e ) and the response from different overlapped electro-active regions were separated. The ac conductivity obeys CBH model for bulk BaMnO 3 sample. Uptake of PEGylated BaMnO 3 NPs alone and loaded with photosensitizer (5-ALA) were examined on Hep2c cell lines. It was observed that PEGylated BaMnO 3 NPs loaded with 5-ALA has higher uptake as compared to 5-ALA. The high uptake was attributed to large surface area of BaMnO 3 NPs. It was also observed that BaMnO 3 NPs are non-toxic when administrated to Hep2c cell lines. BaMnO 3 nanofibers were synthesized for the first time using ES technique. Effect of different polyvinyl pyrrolidone (PVP) concentration on uniformity and homogeneity of nanofibers was investigated.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

کیہڑی وکھری گل سی چال اندر

کیہڑی وکھری گل سی چال اندر
دل کھب گیا اوس خیال اندر
ہووے سچی لگن جے عشق اندر
مزہ ہکو ہے ہجر وصال اندر
اینویں جنگلاں وچ نہ ماریا پھر
کر اندروں پرت کے بھال اندر
رکھ کعبے دے وانگر دل اپنا
مت نفس شیطان نوں پال اندر
جنھاں لٹ کے کھاہدا ملک سارا
آگئے نیں ہن زوال اندر
عشق پک دا نال جفا لوکو
سچا عشق سی جیویں بلال اندر
گئی گزری زندگی عشق دے وچ
بیٹھا ہوندا اے جیویں کنگال اندر
دل حجرا سوہنے رب دا اے
ایہو جئی نہیں کوئی مثال اندر

Students Reading Comprehension Through Scanning Technique

This article reviews how scanning technique contributes to reading comprehension. Reading comprehension is defined as the process by which a person derives meaning from print. Scanning is a device used to locate details. Scanning means glancing rapidly through the text either to search for a specific piece of information The differences of students reading comprehension after treatment are influenced by treatment given to them. It was proven by the result of previous research statistical data analysis which indicated to the students’ progress. Teaching reading by using scanning technique can increase students’ reading achievement.

Development of Students Speaking Skills in the Primary English Classroom

In Pakistan English as a foreign language is being taught from primary classes. Teaching English is based on the grammar translation method - reading and translating the text from English to Urdu both in government and private schools. In such classes teaching is based on rote memorization with little meaningful speaking activities, despite one of the curriculum objectives of teaching English language being to teach students to communicate orally. The purpose of this research was to develop students' speaking skills in the primary classroom. The findings related to pre - intervention stage indicate that the constraints that hinder development of speaking skills were the students' fear of making mistakes, they felt hesitant to speak. This was due to lack of opportunity to practice English in the classroom. The lack of opportunity was due to: a) poor time management; b) too many children in the class; c) pressure of exams and syllabus; d) mechanical, individual and choral speaking activities, i.e. short phrases or one word answers. The seven week intervention helped the students to develop their confidence and fluency of speech. To develop accuracy further would require more time. The intervention revealed that: a) students spoke without hesitations or fear of making mistakes and hence were more confident; b) Students spoke with less pauses, had good flow, used less Urdu and were more coherent i.e. they had much greater fluency. c) students made less grammatical mistakes. For primary students to be fluent in speaking the target language the teacher needs to give more opportunity and create an environment to speak allowing the students to talk about their own experiences.