Low anisotropic (Cu 0.5 Tl 0.5 )Ba 2 Ca 2 Cu 3 O 10-δ (CuTl-1223) phase of Cu 1-x Tl x Ba 2 Ca 2 Cu 3 O 10- δ [CuTl-12(n-1)n]; n=1, 2, 3, ... high temperature superconducting (HTSC) family was synthesized by solid-state reaction method. Nanoparticles (NPs) were prepared separately by different techniques (i.e. co-precipitation, sol-gel, and colloidal solution methods). Different kinds and sizes of NPs such as non-magnetic metallic (Ag, Au), non-magnetic metallic oxide (Al 2 O 3 ) and magnetic ferrite (CoFe 2 O 4 ) were added with different wt.% during the final sintering process of CuTl-1223 superconducting matrix to get the required (NPs) x /CuTl-1223 nanoparticles-superconducting composites. These composites were characterized by different experimental techniques such as x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive x-ray (EDX) spectroscopy, resistivity versus temperature measurements, critical current density (J c ) measurements, magnetic ac-susceptibility measurements, Fourier transform infrared (FTIR) spectroscopy etc. The experimental data were analyzed by different well established theoretical models such as Aslamazov-Larkin (AL), Lawerence-Doniach (LD) and Maki-Thompson (MT) models. It was observed that tetragonal structure and stoichiometry of the host CuTl-1223 superconducting phase remained unaltered after the addition of these NPs, which indicates about the occupancy of these NPs at the inter-granular spaces. Non-magnetic metallic NPs (Ag, Au) have improved the superconducting transport properties (T c , J c , etc) up to certain optimum concentration of these NPs in CuTl-1223 matrix. The improvement in the superconducting properties can be attributed to an increase in the inter-grains connectivity by healing up the inter-grains voids and pores after the addition of these NPs. The improved inter-grains connections can facilitate the carriers transport processes across the inter-crystallite sites due to their metallic nature. But the superconducting volume fraction starts to be decreased after certain optimum inclusion level of these non-magnetic non-superconducting metallic NPs, which causes the suppression of superconductivity parameters. The effects of highly coercive cobalt ferrite (CoFe 2 O 4 ) nanoparticles addition on superconducting properties of CuTl-1223 matrix were also explored. The magnetic behavior of CoFe 2 O 4 nanoparticles was determined by MH-loops with the help of superconducting quantum interference device (SQUID). The resistivity versus temperature measurements showed an increase in T c (0), which could be most probably due to improvement of weak-links by the addition of these nanoparticles. The increase of mass density with xxviincreasing content of these NPs can also be an evidence of filling up the voids in the matrix. But the addition of these NPs beyond an optimum level caused the agglomeration and produced additional stresses in material and suppressed the superconductivity. We observed non- monotonic variation of superconducting properties after the inclusion of nano-Al 2 O 3 particles, which can be associated with inhomogeneous distribution of these NPs at the grain-boundaries in CuTl-1223 matrix. But overall suppression of superconducting properties was attributed to a pair-breaking mechanism caused by reflection/scattering of carriers across these insulating nano- Al 2 O 3 particles present at the grain-boundaries of the host CuTl-1223 matrix. The presence of Al 2 O 3 nanoparticles at the grain-boundaries possibly reduced the number of flux pinning centers, which were present in the form of weak-links in pure CuTl-1223 superconducting matrix. The suppression of activation energy {U (eV)} may be due to weak flux pinning in the nano-Al 2 O 3 particles added samples. The superconducting microscopic parameters (i.e. zero temperature coherence length along c-axis {xc (0)}, inter-layer coupling (J), inter-grain coupling (a) etc.) deduced from fluctuation induced conductivity (FIC) analysis with the help of above mentioned theoretical models explained the experimental findings very well. For example, the increase in the values of inter-grain coupling (a) deduced from FIC analysis is a theoretical evidence of improved inter-grain coupling in the host CuTl-1223 matrix with the increased contents of these nanoparticles. We also calculated the activation energy {U (eV)} of (NPs) x /CuTl-1223 nanoparticles-superconducting composites. The increase in T c (0), J c , U (eV) etc and decrease in normal state resistivity {ρ 300 K (Ω-cm)} were observed after the addition Ag, Au and CoFe 2 O 4 NPs in CuTl-1223 superconducting phase. The suppression of superconducting properties (i.e. T c (0), J c , U (eV) etc) after the addition of Al 2 O 3 nanoparticles in host CuTl-1233 superconducting matrix was observed.
پروفیسر عبد الحق نے تحقیق کے میدان میں اپنا لوہا منوایا اور پھر تنقید کی دنیا میں بھی اردو ادب کی نئی راہوں کا تعین کیا۔ اقبالیات سے شغف تو آپ کے رگ وپے میں سمایا ہوا تھا اس سبب کے باوجود ترجمہ کا کام بھی آپ نے خوش اسلوبی سے انجام دیا۔ ان کا سب سے پہلا ترجمہ ”فضائل ذکر“ کا ترجمہ تھا جو شیخ محمد ذکریاؒ کی تالیف ہے۔ اس کتاب کا انہوں نےانگریزی زبان میں ترجمہ کیا اور اس کا نام )VIRTUES OF REMEMBERING( رکھا۔ آپ ترجمے کا مفہوم کچھ اس طرح بیان کرتے ہیں کہ : ”ترجمے کا مفہوم کسی خیال کا دوسرے تک منتقل کرنا ہے“(20) یہ بات انسان کی عادت میں شامل ہے کہ وہ اپنے افکار و نظریات کو پروان چڑھانا چاہتا ہے۔ وہ ہر لمحہ اس بات میں مگن دکھائی دیتا ہے کہ اس کے ایمان اور عقائد کا دائرہ کار توسیع اختیار کرے۔ دوسروں کو ہمراز اور ہم خیال بنانے کی کاوش میں دیوانگی کی حد تک جا پہنچتا ہے۔ اس کے لیے وہی باعث نجات اور خیر کا موجب ہوتا ہے۔ پروفیسر عبدالحق کی محققانہ ،مدبرانہ اور ناقدانہ رائے یہ ہے کہ یہی بات ، جدو جہد اور خواہش ترجمہ کی تحریک پیداکرتی ہے اور فرماتے ہیں کہ : ”اگر مخاطب ہم زبان اور ہم قلم نہیں ہے تو کسی مشترک زبان اور ذریعہ اظہار کاسہارا لینا پڑتا ہے“ (21) ترجمے کی روایت مسلسل آگے ترقی پا رہی ہے۔ ایک عام سی فہرست کے مطابق اردوزبان میں اب تقریباً اٹھارہ ہزار سے زائد کتب ترجمے کی صورت میں موجود ہیں۔ اس تعداد میں اضافہ ہی ملے گا کمی نہیں ہوگی ۔ ہر زبان نے ترجمے کی افادیت سے متاثر ہو کر اپنے اپنےادبی خزانے میں اضافہ ہی کیا ہے۔ فارسی میں عربی تصانیف کے...
Muslims across the world memorize the Quran in Arabic for verbatim recall. Memorizers can be native speakers of Arabic, non-native speakers of Arabic, or non-Arabic speakers. The purpose of this study is to investigate expert Quran memorizers on their memorization practices including what they brought to the act of memorization and what, according to them, underlay their success in memorization. Ten memorizers were interviewed about their reflections on their memorization practices. The analysis reveals that while some practices of the Quran memorizers are in line with findings from research literature on memory, there are others which are peculiar to them. The conclusion drawn is that Quran memorizers recite accurately because they do not learn the language. It is further concluded that Quran memorization is a special case, in which a range of extra linguistic factors such as identity, motivation and intention play an important role.
The current research was originated by detecting the significance of the language learning strategies (LLS) with relation to the psychological factors. Previous research studies have shown language anxiety to be associated with broad based indices of language achievement. However, to date few researchers have empirically investigated the potential link between foreign language anxiety and language learning strategies. The objectives of current study were multifold. The first was to investigate which language learning strategies were frequently used by Pakistani high school students. The second was to discover the anxiety level of the participants and the third to find out the interaction of anxiety on the use of LLS. 476 high school students of grade 10th belonging to 18 schools (Private, Public, Rural and Urban)of Bahawalpur (Pakistan). Strategy Inventory for language learning (SILL) (Oxford, 1990) was used as an instrument to explore the language learning strategies used. Foreign Language Class Room Anxiety scale (Horwitz, Horwitz & Cope, 1986) was applied as an instrument for measuring the anxiety level of students. Data were analyzed using descriptive analyses, Pearson r correlation, Analysis of variance (ANOVA), T-Test and Cronbach’s alpha. The result of the SILL phase of the research revealed the frequency of strategies used by Private, Public, Rural, Urban, Science, Non Science, Low Proficiency and High Proficiency students. A significant relationship was explored between language learning strategies use and class room anxiety. Interaction of anxiety on language learning strategies was explored under three classes of anxiety as communication anxiety, test anxiety and fear of negative evaluation as stated by Horwitz et al. (1986). Students with medium level of communication anxiety used more memory and cognitive strategies than low and high communication anxiety level students. Students with low communication anxiety level used more cognitive strategies than medium and high communication anxiety level students, while students xi with high communication anxiety level used more affective strategies than low communication anxiety level students. Students with low test anxiety level used more cognitive and meta-cognitive strategies than medium test anxiety level students. High fear of negative evaluation level students used more memory and affective strategies than low fear of negative evaluation level students. The thesis concludes by bringing together the key findings and suggestive areas for further research. In sum, this research provides English language teachers and curriculum planners with ample and validated information about LLS currently used by Pakistani high school students and interaction of anxiety level on LLS use.