آپ ﷺ کی ولادت سے سیدہ آمنہ ؓ کا گھر بقعہ نور بن گیا ۔ عثمان بن العاص ؓکی والدہ فاطمہ ؓ کہتی ہیں کہ میں شب ولادت سیدہ آمنہ ؓ کے پاس تھی ‘ میں نے گھر میں جس طرف بھی نظر دوڑائی مجھے نور ہی نور نظر آیا ۔ صاحب سید الوریٰ بحوالہ علامہ زرقانی بیان کرتے ہیں کہ شفاء بنت عوفؓ جو شب ولادت سیدہ آمنہؓ کے پاس تھیں ‘ کہتی ہیں ’’ میرے لیے مشرق و مغرب روشن ہو گئے ۔‘‘ یہ تمام انوار زمین پر دیکھے گئے جب کہ آسمان سے بھی نور کی برسات ہو رہی تھی ۔ اس منظر کو فاطمہ ؓ یوں بیان کرتی ہیں ’’ میں نے ستاروں کو دیکھا کہ وہ جھکے پڑتے تھے اور مجھے یوں لگتا تھا کہ مجھ پر گر پڑیں گے‘‘ ۔ مزید بحوالہ طبقات ابن سعد اور البدایہ و النہایہ لکھتے ہیں کہ خود سیدہ آمنہ ؓ فرماتی ہیں جب وہ مجھ سے منفصل ہوا تو اس کیساتھ ایک ایسا نور ظاہر ہوا ‘ جس سے مشرق و مغرب روشن ہو گئے ۔ ‘‘ پھر با حوالہ زرقانی ‘ سیرت حلبیہ اور سیرت ابن ہشام لکھتے ہیں ’’ میں نے اس ولادت کی رات کو ایسا نور دیکھا جس کی وجہ سے شام کے محلات ر وشن ہو گئے۔ اور میں نے انھیں دیکھ لیا ۔‘‘
یہاںسوال پیدا ہوتا ہے کہ زمین و آسمان منور ہو گئے ۔ انوار کی برسات کا منظر بی بی آمنہؓ ، فاطمہؓ اور شفا ء کے علاوہ کسی اور کو کیوں نظر نہیں آیا؟ اس کا جواب یہ ہے کہ اللہ تعالیٰ کی مشیت ہے کہ جو چیزیں اللہ تعالی ٰصرف مخصوص لوگوں کو دکھانا چاہے وہ تمام چیزیں حقیقتاََ موجود ہونے کے باوجود عام لوگوں کی نگاہوں سے پوشیدہ رہتی ہیں ۔ قرآن مجید میں...
Stress corrosion cracking (SCC) refers to the damage of mechanical components which are under the combined action of static load and corrosive environment. This phenomenon occurs in various applications including naval and aerospace industry where aluminum and steel alloys experience mechanical loadings in the presence of corrosive environments. In this research work, microstructural and environmental influence on corrosion behavior of Al-6061-T6 at different static loads was investigated. A new test fixture was developed for stress corrosion cracking. Dog-bone shaped tensile specimens of Al-6061-T6 were manufactured using CNC milling machine. Tests were conducted at constant loads of 200 N, 500 N and 800 N, in three different environments: dry ambient conditions, distilled water and 3.5% NaCl solution. Testing continued for different intervals of time i.e. 96 hours, 68 hours and 4.5 hours respectively. After each set of experiments, specimens were observed for cracks using metallurgical microscope. Detailed fractographic investigation of all the tested specimens was carried out using Scanning Electron Microscope (SEM). Excessive corrosion and material degradation was observed in specimens tested in distilled water and 3.5% NaCl environments.
Microstructural analysis depicted pitting corrosion and crack deformation. Some regions clearly showed that grain boundaries were attacked due to oxidation and chemical attack causing weakening of grain boundaries and resulted into intergranular corrosion. Precipitates and grain boundaries in Al-6061-T6 served as a reason of crack initiation due to hydrogen diffusion. Fractographic investigation provided the evidence of trans granular fracture as well as intergranular fracture which was observed as dimples and extensive ductile tearing.
Multidimensional magnetic cobalt ferrite (CoFe2O4) nanoparticles (NPs) were synthesized by a co-precipitation method under the effect of three capping agents called sorbitol, tergitol-1x (T-1x) and didecyldimethyl ammonium bromide (DDAB). The synthesized cobalt ferrite nanoparticles (CFNPs) were functionalized with guar gum (GG), xanthan gum (XG), gum arabic (GA), polymethacrylic acid (PMAA) and were subsequently characterised by Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), X-ray diffraction (XRD) and contact angle studies. Vibrating sample magnetometry (VSM) was used for magnetic measurements of the native and polymers-coated CFNPs. The microstructural morphology of the uncoated and polymers-coated CFNPs was established using scanning electron microscopy (SEM), Transmission electron microscopy (TEM), atomic force microscopy (AFM) and dynamic light scattering (DLS) studies. The antibacterial activity of native and coated CFNPs was also tested against Escherichia coli and Staphylococcus aureus by using disc diffusion method. Furthermore, the interaction of cobalt ferrite nanoparticles with calf-thymus DNA was investigated and characterized by FT-IR. The biocompatibility of naked and coated CFNPs was also examined against normal (CHO) and cancerous (Huh-7) cell lines by performing MTT assay. Finally, the doxorubicin release profile from the drug-loaded functionalised CFNPs in the presence of an externally applied magnetic field was evaluated using UV-visible spectroscopy. The results show that the DDAB is more effective capping agent to control the particle size and dispersion of CFNPs in aqueous medium. Antibacterial activity test and MTT assay exhibited that coated-CFNPs are significantly more biocompatible as compared to native CFNPs. Polymer coating decreased the contact angle of the native CFNPs from 92° to 40°, which indicated that it modified the CFNPs surface from hydrophobic to hydrophilic. VSM analysis demonstrated that polymers coated cobalt ferrite NPs (CoFe2O4.NPs@polymers) also retained the magnetic characteristics of the bare cobalt ferrite NPs (Ms ∼77.2 emu/g), endorsing their application as promising magnetic nanovectors (MNV). The synthesised drug loaded-polymer coated cobalt ferrite NPs, (CoFe2O4.NPs@polymers-Doxo) exhibited significantly higher controlled discharge of doxorubicin at acidic pH (5.0) than at neutral pH (7.4). In vitro cytotoxic studies confirmed the cytocompatibility mode of coated CFNPs against Chinese Hamster Ovary and Huh-7 cell line, while 0.2 mg.mL1- dose of drug loaded magnetic nanocarriers inhibited the cell viability of Huh-7 up to 60%. These results strongly encourage the utilization of biocompatible magnetic nanocarriers (CoFe2O4.NPs@polymers) in targeted drug delivery territory for doxorubicin.