Magnetic Carbon Nanocomposites (MCN) was prepared from pineapple and mango biomass precursors and then characterized by mean of SEM, XRD, FT-IR, TG/DTA, EDX, surface area analyzer and pH (PZC). XRD patterns show the presence of Fe3O4 deposited on the surface of carbon materials with cubic crystalline structure at different 2θ values which corresponds to indices planes. SEM images show the mean diameter of both MCN are around 50-70 nm with equal distribution of white areas in the images of both MCN show the crystallization of nano-particles of Fe3O4, while black spots represent the carbon contents. The BET surface area of pineapple and mango MCN are 43 and 51 m2g-1 respectively and BJH pore size distribution are 17.50 and 21.65 m2g-1 respectively, whereas, the total pore volume and pore diameter of both MCN are 0.015 and 0.019 cm3g-1 and 15.05 and 15.03 Ao respectively. The low surface area is due to impregnation of magnetic particles (Fe3O4), which resulted into pore blockage. The FTIR spectra of MCN shows peaks at 3470 and 3200 cm-1 which may be due to the presence of surface groups such as phenol, carboxylic acids, carboxylic acid derivatives along with physically adsorbed water and surface moisture. The two narrow peaks in the region of 3000-2800 cm-1 correspond to C-H alkanes, peaks at 1450-1600 cm-1 corresponds to C=C aromatic, peaks at 1300-1000 cm-1 corresponds to -OH alcoholic and ether, while the peak at 575-580 cm-1 corresponds to Fe-O of magnetite and maghemite. The pHpzc of pineapple and mango MCN were found to be 7.2 and 7.3 respectively. The removal of antibiotics such as ciprofloxacin (CIP), levofloxacin (LEV) and enrofloxacin (ENR) from the water system was carried out by adsorption (adsorption kinetics and isotherm studies) and MCN-membrane hybrid technology. The adsorption data shows that the equilibrium was established within 220 min. The adsorption kinetics data were applied to both 1st, 2nd order pseudo kinetics and intraparticle diffusion models. Pseudo 2nd order kinetics and intraparticle diffusion models were found best fits to the adsorption kinetics data. Thermodynamic parameters like rate constant (K), ∆?°, ∆?° and ∆?° were determined using the Van’t Hoff equation. It was found that the rate constant increases with rise in temperature. The rate constant (K) trend for the adsorption of antibiotics was found as: LEV>ENR>CIP. Entropy of activation (ΔSo) was found to be positive which shows an increase in randomness at the solid-liquid interface during the adsorption. Enthalpy of activation (∆?°) decreases in the following order LEV>ENR>>CIP for PAMCN, and ENR>LEV>CIP for MAMCN. ΔSo decreased in the sequence of, CIP>LEV=ENR for pineapple nanocomposites and ENR>LEV>CIP for mango nanocomposites respectively. The negative values of ΔG˚ at various temperatures specify the spontaneous nature of the adsorption process and have a high affinity of antibiotics molecules for both nanocomposites. The intraparticle diffusion model shows that the adsorption of antibiotics is a diffusion controlled process. For adsorption isotherm studies the mathematical models like Freundlich, Langmuir, Jovanovich and Tempkin isotherms were used for the determination of adsorption parameters. The isotherm data fitted well to Langmuir model for the adsorption data. The effects of pH, temperature, time, concentration, adsorbent dosage, humic acid and ionic strength on adsorption process were evaluated. The adsorbent after use was regenerated using NaOH, methanol and distilled water. The equilibrium time for both adsorbents at pH 7 was reached in 60-80 min. Improved permeate fluxes and percent retentions of antibiotics by membranes were observed for adsorption/membrane hybrid process MCN/UF (magnetic carbon nanocomposite/Ultrafiltration), MCN/NF (magnetic carbon nanocomposite/ Nanofiltration) and MCN/RO (magnetic carbon nanocomposite/Reverse osmosis filtration). The percent retention of antibiotics molecules in NF was 96% which increased to 100% when membrane was used in hybrid manner with MCN. Which is a great achievement in the present study.
’’اگر مجھے پتہ ہوتا میری حکومت گرانے کے لیے میرے بھائی کو قتل کیا جائے گا ۔تو میں کبھی بھی پرائم منسٹر ہائوس کے لیے نہ لڑتی ۔‘‘
یہ کوئی سیاسی بیان نہیں ایک مظلوم بہن کی اپنے بھائی کے قتل پہ فریاد ہے ۔کنیزِ کر بلا کا یزیدیت کے خلاف مقدمہ ہے ۔مظلومیت کا نوحہ ہے ۔بھٹو خاندان پہ ہو نے والے مظالم ہمار ی تاریخ پہ بد نما داغ ہیں اور اس سے بھی بڑی بے ضمیری یہ ہے کہ قاتل انہیں قتل کرنے کے بعد قتل کا الزام بھی انہی پہ لگاتے رہے ۔
Sūrah al Fātiḥa it is a short Sūrah, yet full of facts and meanings, sweat and heart provoking. This Sūrah is the title of the Qur‘ān and the whole Qur‘ān is its explanation. The fundamental objectives of Qur‘ān, faith and good deeds have been explained in this Sūrah. That is why this Sūrah is also proclaimed as “Umm al Kitāb” and “Umm al Qur‘ān”. Its Scripture is related to worship and help. The worship proceeds to seeking help. The word worship has three meanings: devotion, slavery and submission. Allah Almighty, time and again, ordered towards His submission and worship in the Holy Qur‘ān. It is the esteem of worship on which Allah has honored His Prophet. He is the real Lord and all blessings and powers are for Him. He is Lord of lives and we should have trust in Him and seek help from Him. The separation, individuality and solitude are prohibited in Islam. The verses of Sūrah al Fātiḥa (و ایاک نستعین ایاک نعبد) gives the massage of congregation which is the solution of disturbance and riot. Who so ever wants to go paradise, should have attach to the Ummah.
FACULTY OF INDUSTRIAL ENGINEERING Department of Industrial Engineering Doctor of Philosophy SURFACE FINISH OPTIMIZATION IN FACE MILLING GRADE 5 TITANIUM ALLOY FOR SUSTAINABLE MANUFACTURING By Imran Masood Sustainability achievement of difficult-to-machine materials is major concern now-a-days. In this work the machining sustainability of Ti-6Al-4V hardened up to 55 HRC is assessed through a novel technique of iso-response method, in which the response value i.e. surface finish is taken as criteria for evaluation and comparison among dry, conventional and cryogenic machining. Experiments were designed in DOE for central composite design and performed face milling of Titanium alloy Ti-6Al-4V using PVD coated carbide inserts under three conditions of cooling and measured the response values. Feed, speed and depth of cut were used as input parameters. The parameters giving nearly same response values in each scenario were used to evaluate the sustainability of each mode for cutting power, machining time, material removal rate, tool life and machining cost. Comparing the average results achieved by cryogenically cooled experiments, it is found that 61.9% less cutting power, 15.12% less machining time , 47.55 % less electricity cost and 47.59% less machine operating cost observed for cryogenically cooled experiments as compared with dry machining. Coolant cost is found 13.33 times cheaper for cryogenic as compared with conventional machining. Whereas increased material removal rate of 81.12% and increased cutting tool life by 5.2 times for cryogenic machining as compared to dry one. Furthermore on comparison of cryogenic machining with conventional machining, it is found that cutting time is saved by 3 %, cutting tool life is increase by 1.34 times, electricity cost is saved by 39 % and labour cost is saved by about 38%. iv The results indicate that cryogenic cooling is more sustainable as compared to dry and conventional cooling process. It was found that the cryogenic machining gives the best results for tool life, surface finish of machined part, productivity with least impact on the environment, least energy cost and machining cost. Findings of this research are helpful in assessing sustainability for machining industry to reduce tooling cost, machining cost, worker’s health problems, environmental impact and will help to select sustainable input parameters. The proposed model gives the machining industry a unique direction to adopt the sustainable input parameters.