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Home > Fabrication and Physical Characterization of Ni1-Xznxfe2o4 and Cu1-Xznxfe2o4 Ferrites

Fabrication and Physical Characterization of Ni1-Xznxfe2o4 and Cu1-Xznxfe2o4 Ferrites

Thesis Info

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External Link

Author

Muhammad Ajmal

Program

PhD

Institute

Quaid-I-Azam University

City

Islamabad

Province

Islamabad.

Country

Pakistan

Thesis Completing Year

2008

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/431

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726188693

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The effects of zinc substitution on the nickel based and copper based spinel ferrites have been investigated. Three series of spinel ferrites with nominal compositions Ni1-xZnxFe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0), Cu1-xZnxFe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0), and Ni0.8-xCuxZn0.2Fe2O4 (x = 0.0, 0.2, 0.4, 0.6, 0.8), were prepared by the conventional solid state reaction technique. The samples were characterized by SEM, X- ray diffraction, DC electrical resistivity, dielectric properties and magnetic properties measurements. Grain size was measured from the scanning electron micrographs. The average grain size of sintered ferrites was within the range of 2.36-6.16 μm, 26.75-3.25 μm, and 3.15-26.75 μm, for Ni-Zn, Cu-Zn and Ni-Cu-Zn ferrites respectively. The X-rays diffraction was done through PANalytical diffractometer using Cu Kα radiations (λ = 1.054Å). Lattice constant increased with the increase in zinc concentration in case of Ni1- xZnxFe2O4 and Cu1-xZnxFe2O4 ferrites, whereas it increased with the increase in copper concentration in case of Ni0.8-xCuxZn0.2Fe2O4 ferrites. Sintered density increased with the increase in zinc concentration in case of Ni1-xZnxFe2O4 and Cu1-xZnxFe2O4 ferrites whereas it increased with the increase in copper concentration in case of Ni0.8-xCuxZn0.2Fe2O4 ferrites. X-ray density decreased with the increase in zinc concentration in case of Ni1-xZnxFe2O4 and Cu1-xZnxFe2O4 ferrites whereas it decreased with the increase in copper concentration in case of Ni0.8-xCuxZn0.2Fe2O4 ferrites. Porosity decreased with the increase in zinc concentration in case of Ni1-xZnxFe2O4 and Cu1- xZnxFe2O4 ferrites whereas it decreased with the increase in copper concentration in case of Ni0.8-xCuxZn0.2Fe2O4 ferrites. DC electrical resistivity measurements were carried out by two-probe method from 300 K to 540 K in case of Ni-Zn ferrites, 320 K to 520 K in case of Cu-Zn ferrites and 305 K to 603 K in case of Ni-Cu-Zn ferrites. Activation energy and drift mobility were also calculated from the measured resistivity. The dielectric constant was measured as a function of Zn substitution in Ni-Zn ferrites as well as a function of Cu concentration in Ni-Cu-Zn ferrites. The dielectric constant and dielectric loss factors were measured as a function of frequency for all the samples in the range of 80 Hz to 1 MHz at room temperature. The ac conductivity σac in case of Ni-Zn ferrites was also measured. To measure the magnetic properties of the prepared materials, the M-H loop of the specimen were drawn. From the M-H loop of the sintered materials, we measured saturation magnetization. Magnetic moment, coercivity and Yafet-Kittel angles were also calculated. Saturation magnetization increased up to x = 0.4 and then decreased with the further increase in Zn concentration in case of Ni-Zn and Cu-Zn ferrites whereas it decreased with the increase in Cu concentration in case of Ni-Cu-Zn ferrites. The magnetic moment also had the similar trend. Coercivity decreased with the increase in Zn concentration in case of Ni-Zn and Cu-Zn ferrites. The Yafet-Kittel (Y-K) angles initially had zero value and then increased with the rise in Zn concentration for x > 0.2, x > 0.4, x > 0 in case of Ni-Zn, Cu-Zn and Ni-Cu-Zn ferrites respectively.
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دل محمد دلشاد

دل محمد دلشاد (۱۸۰۰ء پ) گلی حکیماں محلہ سیداں (کوچہ بند) پسرور میں پیدا ہوئے۔ آپ اپنے فارسی اشعار میں ایک جگہ اس کی طرف اشارہ بھی کرتے ہیں :

یکے دو دست عجب تال آپس شش پہلو                        بشش جہات بہ پنجاب گو کہ ثانی آں است   

دلیل شادی دلشاد نام ایں شہراست                             کہ پر سرور طرب بخش عالم دل و جاں است  (۱۱)

آپ فارسی اور اردو کے بہترین شاعر ہونے کے علاوہ عالمِ دین بھی تھے۔ دلشاد کے کلام میں حد درجے کی پختگی اور سادگی عیاں ہے۔ وہ اپنی تشبیہات اور استعارے حالاتِ حاضرہ اور دیگر نشیب و فرازِ حیات سے اخذ کرتے ہیں۔ ان کے کلام میں بے حد جاذبیت اور شرینی موجزن ہے۔ اُن کا زیادہ کلام قصائد اور غزلیات پر مشتمل ہے۔

قاضی عطاء اﷲ اپنی کتاب ’’شعرائے پسرور‘‘ میں دلشاد کے بارے میں رقمطراز ہیں:

دل محمد دلشاد پسروری انیسویں صدی کے معروف فارسی اور اردو شاعر ہیں۔ آپ نے متداولہ علوم و فنون اغلباً سیالکوٹ جیسے علم و حکمت کے شہر سے حاصل کئے۔ منطق ‘ سلوک‘ اخلاق‘ فقہ اور شعری علم میں کمال حاصل کیا۔ (۱۲)

مذکورہ بالا علوم میں مہارت دلشاد کے ایک فارسی شعر سے واضح ہوتی ہے:

از علم شعر و منطق‘ فقہ و سلوک و اخلاص                    دارد تمام لیکن دلشاد زر نہ داد       (۱۳)

آپ کا زیادہ تر اردو کلام مفقود ہے۔ مختلف اردو تذکروں میں آپ کا کلام ملتا ہے۔ آپ کا فارسی دیوان ادارہ تحقیقاتِ پاکستان دانشگاہ پنجاب لاہور نے ۱۹۷۰ء میں شائع کیا۔ (۱۴) عشقِ مجازی‘ محبوب کی بے اعتنائی‘ بے وفائی‘ عشوہ وغمزہ وادا دلشاد کی اردو غزلوں کے موضوعات ہیں۔ حافظ محمود شیرانی نے اپنی تالیف ’’پنجاب میں اردو‘‘ میں دلشاد کی چند غزلیں نقل کی ہیں۔ ان اشعار میں دلشاد اپنے محبوب سے شکوہ کرتے نظر آتے ہیں۔ کلاسیکی اردو شاعری کے روایتی محبوب کی طرح...

دراسة وتحليل استراتيجيات الفهم الشفهي عند الطفل يعاني صعوبات تعلم القراءة

تهدف الدراسة إلى تحليل استراتيجيات الفهم الشفهي عند الطفل الذي يعاني صعوبات تعلم القراءة. تكونت عينة الدراسة من 40 طفل متمدرسين وموزعين على مجموعتين: مجموعة ضابطة (قراء عاديين) ومجموعة تجريبية (أطفال يعانون صعوبات تعلم القراءة)، وقد استخدمت الباحثة في هذه الدراسة الاختبارات التالية: اختبار الذكاء، اختبار القراءة، وأخيرا اختبار الفهم الشفهي. وتوصلت الدراسة الى النتائج على ما يلي: وجود فروق ذات دلالة إحصائية بين المجموعتين في استراتيجية الصرفي النحوي، والاستراتيجية القصصية. ووجود فروق ذات دلالة إحصائية بين المجموعتين في الاستراتيجية التحتية الفورية والكلية. كما أنَّ الاستراتيجية التحتية الفورية تؤثر على الاستراتيجية التحتية الكلية، وهذا في المجموعة التجريبية.

Analysis of Genetic Diversity in Grey Langur Semnopithecus Spp. Populations of Pakistan

Grey langurs (Semnopithecus spp., Colobinae, Cercopithecidae, Primata, Mammalia) is a group of the old-world leaf eating monkeys widely distributed in the Indian subcontinent, with two species viz. Semnopithecus ajax and S. schistaceus reported from higher altitudes of the Himalayan hills extending into northern Pakistan. Species status of these populations is still debated, though S. ajax is regarded as Endangered globally. In Pakistan, small declining population of these grey langurs is distributed in pockets, but the level of isolation is still unknown. To resolve such uncertainties, the present study was undertaken to assess intrapopulation genetic diversity, and to settle taxonomic status of different populations, using modern molecular biology tools. We collected 86 noninvasive (feces 64, hair 13, blood 5, tissues 4) samples from 5 geographic langur populations of Pakistan and Azad Jammu and Kashmir (AJK) and succeeded in extraction of DNA from 23 samples, which were used for further genetic analysis. We used nuclear (Random Amplified Polymorphic DNA-RAPD and microsatellites) and mitochondrial DNA (Cytochrome oxidase-I, Cytochrome b and 16S rRNA) markers. RAPD makers (n=8) produced 245 bands (30.62±2.87 mean±SE / primer) of different molecular weights (126-3342 bp), of which, 96 were population specific. Polymorphism was (37.71±5.29%; mean ± SE), with the highest in Muzaffarabad population (54.29%), followed by Poonch (43.67%) and Neelum (36.73%). Values of Shannon’s (I: 0.129-0.200) and Nei''s genetic diversity (He: 0.082-0.117) indices were low. Total heterozygosity (Ht: 0.144±0.007), genetic diversity within population (Hs: 0.096±0.005), between populations (Dst: 0.018±0.003), genetic differentiation constants among populations (Gst: 0.153±0.025) and within populations (Rst: 0.847±0.025) were calculated. Gene flow (Nm: 3.246 0.448) and genetic similarity (97-98%) between populations was high. UPGMA (unweighted pair group method with arithmetic mean) based dendrogram identified five distinct geographic groups, and Mantel tests (Rxy=-0.008, P>0.05) suggested a non-significant relationship between genetic distance and geographic distance. Phist (FPT) value suggested a significance difference within population and between populations (FPT=0.042; p=0.006) variances, suggesting that within populations variation was higher (96%) than variation between populations (4%). Microsatellite analysis, using 16 primers, exhibited successful cross-species amplification suggesting high discriminatory powers (PIC = 0.94±0.01). A total of 256 polymorphic bands comprising on 97 different sized (88-383 bp) alleles (2-10 alleles/marker) were amplified in different genotypes sampled. Mean level of polymorphism in different populations was 45±6.06%. Tests for linkage disequilibrium between different loci exhibited no significant deviations from expected values (p>0.05). Mean values of Shannon’s (0.357±0.05), Nei’s genetic diversity (0.241±0.03), fixation indices (-0.894±0.03), genetic differentiation coefficient (Fst: range = 0.223 - 0.898, mean = 0.438±0.097) and mean gene flow (1.185±0.374) were calculated. The largest Nei’s genetic distance (0.752) was between Mansehra and Neelum populations, while the least (0.255) between Mansehra and Kohistan populations. UPGMA based dendrogram identified two main clusters, Cluster one subdivided into Poonch population (as outgroup) and a monophyletic clade of Muzaffarabad and Neelum populations. Second cluster included Mansehra and Kohistan populations. Principal Coordinates Analysis (PCoA) also indicated three clusters: (1) AJK (Muzaffarabad-Neelum-Poonch), (2) Mansehra, and (3) Kohistan. The value of Rxy=0.302 (P<0.01) revealed a significant association between genetic distance and geographic distance. Phylogenetic analysis, based on different mitochondrial genes partial sequences (COI, Cyt b and rDNA), using Maximum likelihood, Neighbor-Joining, and Minimum Evolution methods, suggested close relationship of grey langurs of Pakistan with S. schistaceus and S. entellus populations from different regions of the Indian subcontinent. Estimated evolutionary divergence values showed a low genetic distance (<0.01) indicating that different populations belong to a single species. Analysis for species delimitation using 4×-rule or K/ϴ (D/ϴ) method also indicated status of a single species. Present study suggested a low level of isolation and inbreeding between grey langur populations of Pakistan and Azad Jammu and Kashmir. This study confirmed that Semnopithecus ajax is the only species found in different areas of Pakistan and AJK. Further molecular, as well as morphological, studies using larger sample size and analysis of complete mitochondrial genome sequences are suggested.