Natural surfactants are amphiphilic compounds derived from natural resources mainly plants and microorganism. Owing to their excellent physiochemical properties they are replacing synthetic surfactants in verity of commercial applications. In present study natural surfactants obtained from bacteria and two plants were studied for their possible role in rehabilitation of crude oil contaminated soils. In first phase of this study a biosurfactant producing bacterial strain was isolated from crude oil contaminated soil samples of Missa Kaswal oil field. Out of 51 bacterial strains only seven were found to be surfactant producing. The most efficient biosurfactant producing strains were including; M8, M9 and M10 based upon surface tension reduction, emulsification index, oil displacement and drop collapse test. The strain M9 showed highest reduction of surface tension of the culture medium i.e. 66.7 to 26.6 mN/m and 6.2 cm of oil displacement zone considered as the most efficient biosurfactant producing bacteria. The isolates M8, M9, and M10 identified by using morphological, biochemical and molecular techniques as different strains of Pseudomonas aeruginosa. Out of four different media, medium 4 proved to be the best in term of yielding highest amount of biosurfactants with all the three strains of Pseudomonas aeruginosa. Biosurfactant production was 2.31 g/L in medium 4, after 96 hrs by strain M9, whereas strain M8 and M10 produced relatively less biosurfactants. The strain M9 was the most efficient and selected for further studies. Optimization of different carbon sources revealed glycerol as the best in medium for the highest bacterial growth 1.37 g/L and biosurfactants production 2.890 g/L. The rhamnolipid production reached up to 4.44 g/L at optimum conditions i.e., pH 7, temperature 34 ˚C, agitation speed (rpm) 155, and 2.8 % inoculum. The media components were also optimized by using a combination of response surface and central composite design. The optimized medium composition pertaining to maximum rhamnolipids production of 5.67 g/L was obtained by using NaNO3 3.92 g/L, KH2PO4 2.3 g/L , MgSO4 0.26 g/L and FeSO4 0.0028 g/L. The chemical composition of biosurfactant produced by P. aeruginosa M9 was determined using HPTLC, FTIR and MALDI-Tof techniques. Results indicated that strain M9 produced a mixture of RL-1 and RL-2 during its growth on glycerol. The rhamnolipid produced by P. aeruginosa M9 were studies under effect of varying pH, salt concentration and temperatures. Results suggested that rhamnolipids retained their activity between pH 4-10, 1-21 % NaCl and 121 ˚C. In addition, 0.2 % of the crude rhamnolipid was sufficient to decrease the surface tension of the waster to 26.6 mN/m. The n-butanolic extract of S. mukorossi and A. concinna were analyzed for the presence of saponins using TLC and FTIR spectroscopy. The results indicated presence of saponins in both the plants. Results indicated that saponins from S. mukorossi and A. concinna were stable at pH 4-9, 25-121 ˚C, and 1-21 % NaCl. The crude saponin extracted from S. mukorossi reduced the surface tension of the water to 39.1 mN/m at a concentration of 0.2 % (w/v). On the other hand, surface tension Acacia saponin reduced the surface tension to 42.0 nM/m. The role of natural surfactants obtained from microbial and plants resources were studied in surfactant enhanced soil remediation by using Taguchi’s Orthogonal Array Design. Removal of crude oil from the soil collected from Missa Keswal oil field was determined under the effect of different temperatures, shaking speed, surfactant concentration and time. Results indicated 94 % reduction in crude oil from the soil at 55°C, 200 rpm, 1% rhamnolipid concentration after 15 hrs. In case of Sapindus saponins, maximum removal was 87 % at optimum conditions of; 65 °C, 200 rpm, 0.8 % saponins and 15 hrs of process time. The results of soil washing using Acacia saponins revealed that 65°C, 200 rpm, 0.8 % saponin and 15 hours were the optimum soil washing conditions pertaining to a maximum removal of 78 % crude oil from the soil. The soil obtained from GCU garden was washed at optimized condition obtained for each natural surfactant. Maximum removal of 81 % was carried out by Sapindus saponins, followed by 78 % by rhamnolipids and 67 % using Acacia saponins. These findings suggested that natural surfactants have excellent potential to be used in soil remediation of complex hydrocarbons such as crude oil.
گلوبل وارمنگ اور ہماری ذمہ داریاں ڈاکٹر عبدالمنان چیمہ گلوبل وارمنگ، جسے عالمی درجہ حرارت میں اضافہ بھی کہا جاتا ہے، زمین کے موسمی نظام میں مسلسل بڑھتی ہوئی حرارت کا عمل ہے۔ اس کی بنیادی وجہ گرین ہاؤس گیسوں جیسے کاربن ڈائی آکسائیڈ، میتھین، اور نائٹروس آکسائیڈ کی مقدار میں اضافہ ہے، جو انسانی سرگرمیوں، مثلاً فوسل فیولز کا جلانا، جنگلات کی کٹائی، اور زراعت سے پیدا ہوتی ہیں۔ گلوبل وارمنگ کی بڑی وجہ ماحولیاتی آلودگی میں بے پناہ اضافہ ہے۔ماحولیاتی آلودگی سے مراد قدرتی ماحول میں ایسے اجزاء شامل کرنا ہے جس کی وجہ سے ماحول میں منفی اور ناخوشگوار تبدیلیاں واقع ہوں۔ زمینی درجہ حرارت میں اضافہ کی بنیادی وجہ ماحول میں انسانی مداخلت ہے۔ ربِ کائنات نے قدرتی وسائل سے مالا مال کیا ہے لیکن جدید انسان سرمایہ کی حرص میں اس صاف ستھرے ماحول میں بعض ایسے مضر اجزاء یا مادّے شامل کررہا ہے، جس کی وجہ سے ماحولیاتی و موسمیاتی تبدیلیاں وقوع پذیر ہورہی ہیں۔ ماحولیاتی تبدیلیاں نہ صرف امراض میں اضافے کا سبب بن رہی ہیں بلکہ انسانی جسم کا دفاعی نظام بھی بُری طرح متاثر کررہی ہیں۔ موسمیاتی تبدیلیاں بالواسطہ یا بلا واسطہ طور پر ہماری زندگیوں میں منفی کردار ادا کرتی ہیں۔ماحولیاتی آلودگی نےہر جان دار کو اپنے شکنجے میں لے رکھا ہے۔ ماحولیاتی آلودگی کے نتیجے میں مختلف بیماریوں مثلاً پھیپھڑوں کے امراض، دَمے، تپِ دق، دِل، جِلدی اور آنکھوں کے امراض کی شرح میں مسلسل اضافہ ہورہا ہے۔ ریسرچ پورٹس کے مطابق دُنیا بَھر میں روزانہ لاکھوں افراد ماحولیاتی آلودگی کی وجہ سے مختلف عوراض کا شکار ہورہے ہیں۔ ان میں سانس کا مسئلہ، دَمہ، سینے کا انفیکشن،ہارٹ انفیکشن ،ہائی بلڈ پریشر،جلدی امراض، ہارٹ اٹیک اور فالج وغیرہ شامل ہیں۔ توانائی کے لئے وسیع پیمانے پر فوسل فیولز کا استعمال درجہ میں اضافے کی بڑی وجہ ہے۔ٹرانسپورٹ کے...
This paper attempts to discuss Aristotle’s concept of justice as an ethical solution to political corruption. The goal of this paper is to present corruption as a form of injustice that deprives the majority from a common good. This paper is very important because it provides ethical solution to grand corruption whereby unscrupulous individuals divert funds meant for development of the entire society into private hands. Due to grand corruption the poor masses are deprived of quality basic needs. The paper focuses on corruption as an immoral act through the lens of Aristotle’s ethical and political insights. The virtue of justice in Aristotle’s ethical and political works are spelled out. The methodology used in this paper is analytical and applied. It is analytical because it analyses Aristotle’s understanding of virtue of justice in his moral theory especially in his book entitled Nicomachean Ethics and justice in his political theory. Finally, the paper makes subsequent applications of Aristotle’s virtue of justice in the realm of ethical solutions to the problem of corruption.
The work presented in this thesis shows the study of different parameters of ion beam emanated from a conventional 2.3 kJ plasma focus device which are used for the deposition of thin films on zirconium substrate. These energetic ions are characterized by employing BPX65 photodiode detector placed at 9 cm along the anode axis and is used to estimate ion energy (range from 40 keV to 1.2 MeV) and ion number density (9.7×1019 m- 3 to 1.796×1019 m-3) of the ions emitted during one focus shot. The relativistic electrons emitted from DPF device play a vital role to incorporate the third element (ablated from the insert material placed at the anode tip by the bombardment of relativistic electrons) into the substrate matrix and to deposit composite films on different substrates. The composite films are characterized by employing different characterization techniques such as XRD, SEM, EDS, Raman Spectroscopy and Vickers microhardness tester to explore the diverse surface properties (crystal structural, surface morphology, crystallite size, microstructure features, elemental compositions and surface microhardness) of the composite films. TRIM code and micro-indentation measurements are used to estimate the depth profile of the modified layers. Nitriding of zirconium by employing the energetic nitrogen ions emanated from plasma focus device for multiple focus shots when the samples are placed at different angular positions confirms the formation of zirconium nitride films on zirconium substrate. The crystallinity and crystallite size of nitride phases increase with the increase of focus deposition shots while residual stresses are maximum at lower nitrogen content (lower number of focus shots) which decrease with the increase of nitrogen contents. Smooth and uniform surface morphology showing granular features of nitrides is observed at 10o. The nitrogen content in the deposited films increases with the increase of focus deposition shots. The microhardness of the deposited film enhances up to 400% and increased by increasing the nitrogen ion dose and decreases rapidly by increasing the angular position. Hence different features of the deposited films are strongly influenced by ion energy flux, ion number density and sample angular position. The XRD patterns of zirconium oxynitride nanocomposite film (deposited for 40 focus shots at different axial positions) show that the crystallinity of ZrN, Zr3N4 and ZrO2 xvii depends on the sample axial position as well as ion energy flux. The SEM images show the formation of compact layer at lower axial position which is due to high ion energy flux. The nitrogen content decreases with the increase of sample angular position. The maximum microhardness of the layers is found to be 7200 ± 12 MPa for 10 gram imposed load. The EDS exhibits the distribution of different elements present in the composite films. ZrAlON composite films are deposited on zirconium substrate showing the formation of ZrN, Al2O3 and AlN compounds. Five focus shots are sufficient to initiate the nucleation of ZrN and Al2O3 while 10 focus shots are enough to initiate the nucleation of AlN. The crystal growth of nitrides/oxides increases with increasing focus shots (up to 30 focus shots) and after that re-sputtering of the previously deposited film takes place. Smooth surface is observed for 20 focus shots at 0o angular position while net type microstructure is obtained for 30 focus shots. Rough surface morphology is observed for 40 focus shots. A typical microhardness value of the deposited composite films is 5255 ± 10 MPa for 10 grams imposed load which is 3.3 times the microhardness values of unexposed sample. The microhardness values of the exposed samples increase with increasing focus shots (up to 30 Focus shots) and decrease for 40 focus shots due to re-sputtering of the previously deposited composite film. Nanocrystalline zirconium carbonitride (ZrxCNy) composite films composed of ZrN, Zr2N and Zr3N4, ZrC and Zr2CN compounds are deposited on zirconium substrate at room temperature for multiple focus shots. The average crystallite sizes estimated for ZrN (200) and Zr2CN (111) planes are found to vary from 10 to 20 nm. Maximum compressive stresses (~ 3.9 GPa) in Zr2N (002) plane for 30 focus shots while maximum tensile stresses (~ 6.5 GPa) in ZrN (200) plane for 20 focus shots are observed. Tensile stresses in Zr2CN (111) plane are transformed to compressive one after 30 focus ion irradiation. Raman analysis exhibits the emergence of D and G bands relating to carbides phases during the deposition process. The SEM microstructure shows agglomerates of size 30 to 300 nm. The Vickers microhardness values of the composite films increase with the increase of focus shots and is found to be 5.6 ± 0.45 GPa for 10 g imposed load which is 4.5 times that of the untreated substrate and 1.5 ± 0.11 GPa for 200 g imposed load which is 1.3 times that of the virgin one. Zirconium silicon nitride composite films consisting of Si3N4 and Zr3N4 compounds are deposited on silicon substrate at room temperature through the reaction of sputtered silicon by ion beams and ablated zirconium from the insert by using plasma focus device. The crystallinity of Si3N4 and Zr3N4 compounds increases with increasing ion irradiation. The crystallite size of nitride increases (from 9 ± 1 nm to 33 ± 3.5 nm) while % microstrain values developed in the nanocomposite films decrease (from 3.65 to 0.61) with increasing focus shots. The SEM images reveal different microstructure patterns like granular, oval and cauliflower types of the deposited films. It is found that crystal growth and stress relaxation inhibit the pit formations during the deposition process. The EDS results confirm the presence of silicon, zirconium, nitrogen and oxygen in the composite films.