Studies were aimed at developing a microbial process for removal of organic sulfur from fossil fuels using model organic sulfur containing compound like dibenzothiophene (DBT), which is believed to be found abundantly in structural matric of fossil fuels. For microbial isolation, different types of soil, sea sand, water, coal and oil sludge samples were collected from various locations. From these samples, 110 bacterial isolates of varying characteristics were screened for their dibenzothiophene (DBT) desulfurizing activity. Only isolate Eu-32, isolated from a soil sample taken from the roots of a Eucalyptus tree, displayed DBT desulfurizing activity. The Eu-32 isolate metabolised DBT to 2-hydroxybiphenyl (2-HBP), as detected by HPLC, and was also able to use other organic sulfur compounds as a sole sulfur source. Based on morphological, biochemical and molecular studies, it was found that this organism belonged to the genus Rhodococcus; with a maximum 95% identity to species in this genus for the partial sequence of the 16S rRNA gene. The structure and molecular mass of metabolites produced from DBT desulfurization were identified by GC-MS, indicating that this isolate followed 4S (sulfoxide-sulfone-sulfinate-sulfate) pathway for sulfur metabolism. However, a novel metabolite identified as biphenyl was also found as end product via a new proposed pathway in this study. The newly isolated Rhodococcus spp. (Eu-32) was used for biodesulfurization of fossil fuels i.e. coal and diesel oil. Shake flask studies were optimized for pH, pulp density, agitation speed and particle size using representative coal sample from Dukki, Baluchistan. The maximum desulfurization of 40% was achieved using coal particle size of 850μm with 10% pulp density, 30oC temperature, pH 7.0 at 180rpm in 15 days. For Dandot coal sample the total and organic sulfur contents were decreased by 32% and 40% respectively when compared to untreated coal under similar conditions. Moreover, the carbon contents and the calorific value (CV) of the biotreated coal were increased by 2.9% and 0.19% respectively. Similarly, biotreatment enhanced hydrogen and nitrogen contents of the coal as 3.9% and 9.9% respectively. Biodesulfurization of coal in 1L locally fabricated fermentor under controlled conditions resulted in a total of 15% decrease of total sulfur in 21 days. ix PhD thesis Nasrin Akhtar The Rhodococcus spp. (Eu-32) did not indicate considerable reduction of sulfur contents in case of experiments on diesel oil. In shake flask studies, only 6% decrease in total sulfur was observed. The Fourier Transform Infrared spectroscopic analysis of biodesulfurized diesel oil revealed that transmittance intensity of the sulphones, sulfonates, sulfates and sulfonic acids were slightly increased in the spectra of the biotreated oil sample validating a slight reduction of these molecules in the diesel oil. For the isolation and identification of C-S bond cleaving genes (dszABC genes) of Rhodococcus spp. (Eu-32), two types of primers (non-degenerate and degenerate) were used. Specificity of the PCR primers and sensitivity of the polymerase chain reaction were checked using a culture of Rhodococcus erythropolis IGTS8 as a positive control for these genes (gift from Dr. John Kilbane, USA). The dszA gene (494bp) of isolate Eu-32 showed that the most closely related sequence was from Rhodococcus erythropolis PR4 with 92% sequence identity to a putative FMNH-2 dependent monooxygenase. The dszB gene showed sequence homology with genome sequences of Rhodococcus species conferring different genes, while the dszC gene sequence (774bp) showed 100% homology with desulfurizing enzyme of Rhodococcus species. It was concluded that isolate Eu-32 is a unique and novel organic sulfur utilizing biocatalyst that desulfurized DBT through an extended sulfur-specific degradation pathway with the selective cleavage of C-S bonds. The genome components required for biodesulfurization activity are functional even present in highly divergent form as compared to desulfurizing genes, which have been documented by other workers. The newly isolated organic sulfur removal bacterium Rhodococcus spp. (Eu-32) could be effectively used for the removal of organic sulfur from fossil fuels, particularly from coal.
گزشتہ ایک برس کے دوران میں کووڈ کی وجہ سے آن لائن لیکچر دیتے ہوئے وہ کئی تجربات سے گزرا۔ پہلے پہل وہ اپنے دھیان میں لیکچر دیتا رہا۔ کچھ دنوں بعد اسے کیمرہ آف ہونے کے باوجود سٹوڈنٹس کی موجودگی اور عدم موجودگی کا اندازہ ہونے لگا۔ کبھی کبھی وہ کسی طالب علم کی موجودگی کی تصدیق کے لیے سوال بھی پوچھ لیتا تھا اور اس کا اندازہ درست نکلتا تھا۔ آہستہ آہستہ اسے مکمل ادراک ہونے لگا کہ کیمرہ آف ہونے کے باوجود کون سٹوڈنٹ موجود ہے اور کون لنک جوائن کرنے کے بعد سو گیا ہے ۔ ذہنی رابط برقی رابطے سے زیادہ موثر محسوس ہونے لگا۔ وہ کیمرہ آف ہونے کے باوجود دیکھنے پر قادر ہو گیا۔ کسی سٹوڈنٹ کا تصور کرتے ہی اس چہرے پر ہویدا اداسی ، بیزاری ، انہماک، دلچسپی اور نیم دلی سمیت دیگر کیفیات کا انکشاف ہونے لگتا تھا۔ وہ صرف غور سے آئی ڈی کی طرف دیکھتا اور سٹوڈنٹ کی ذہنی کیفیت ظاہر ہو جاتی۔ وہ مخاطب ہوئے بغیر کسی سٹوڈنٹ کی کیفیت پر رائے دیتا اور پھر متعلقہ سٹوڈنٹ کی حیرت کو انجوائے کرتا تھا۔ وہ دوران تدریس بہت سے تجربات سے گزرا ۔ اس کے دل میں ایک خیال زور پکڑنے لگا ۔ اس نے خیال کو جھٹکنے کی کوشش کی مگر ناکام رہا۔ اسی خیال کے زیرِ اثر ایک دن اس نے تمام سٹوڈنٹس کو کیمرے آن کرنے کا کہا ۔ سٹوڈنٹس اپنے اپنے کیمرے آن کر بیٹھ گئے ۔ وہ سب کو دیکھ سکتا تھا مگر اسی لمحے اسے شدید دھچکا لگا ۔ وہ کسی بھی سٹوڈنٹ کی کیفیت کو پڑھنے سے قاصر تھا ۔
In the context of blasphemy issue, the present study examines the socio-cultural elements in the Moral Ethics syllabi functional at the different universities of Pakistan. As per our hypothesis, ME syllabi lack some important socio-cultural elements responsible for handling hate crimes, especially the issue of blasphemy. For testing the proposed hypothesis, available ME syllabi were collected from the official websites of different universities. Collected ME syllabi were examined through the method of content analysis. After examining literature review, necessary socio-cultural factors (SCFs) were listed and the selected syllabi were evaluated through this list of SCFs. Our study findings endorse the primary hypothesis that majority of universities has adopted the foreign model of ME syllabi without adapting them according to indigenous social and cultural needs. Additionally, the most important SCFs; knowledge of blasphemy laws (KBL) and real-life dilemmas (RLD), are mostly absent in the existing ME syllabi.
Teachers have been teaching students through conventional teaching method since past many years. Everyone acknowledges that the conceptual understanding of the content is not possible under a threatening classroom environment wherein rote-learning is a common practice. The present day learner is a member of social media age which promotes availing the latest information and discarding the orthodox ideas. This study compares effectiveness of the conventional teaching method i.e. the lecture method with an innovative teaching method known as brain based learning (BBL) teaching method to teach Mathematics at secondary level. All the 9th class students studying the subject of Mathematics at secondary level in Pakistan were the population of the study. Two secondary schools were selected through purposive sampling for smooth conduct of the experiments of the study at rural and urban areas. The independent variable of teaching methodology was manipulated into BBL and conventional teaching methods for the experimental and control groups respectively. An overall sample of 120 students was taken from both of the selected schools. Sixty students each of 9th class were selected independently from each of the two selected schools through the normal distribution of their 8th class annual examination scores. These 60 students were divided equally into experimental and control groups through simple random sampling. Thereafter, 60 students each of experimental and control groups were further categorized equally as high achievers, average achievers and low achievers through systematic random sampling. A 2×3 factorial design was followed to conduct the study because the study contained two factors, namely teaching methodology and academic achievement. Three chapters of 9th class mathematics textbook, containing 15 subtopics altogether, were selected to teach the selected students. The researcher developed 38 lesson plans each in light of the principles of BBL teaching method as well as conventional teaching method to teach the students of experimental and control groups respectively. A standardized 16- item academic achievement test, based on five innate faculties of human brain was administered to each group as pre-test as well as post-test. The difference between post- test and pre-test scores of each selected student was taken as academic achievement of the concerning student. The results of the study proved effectiveness of BBL teaching method as compared to the conventional teaching method for the students of the rural school (F (1, 28) = 146.46, p < .005) as well as for the students of urban school (F (1, 28) = 78.73, p < .005). It was observed that BBL teaching method was more effective than conventional teaching method for high achievers (t (18) = 7.877, p < .005) of the rural school. The same effectiveness of BBL teaching method was noted for the average achievers (t (18) = 5.399, p < .005) as well as for the low achievers (t (18) = 8.918, p < .005) studying in secondary school at the rural area. For urban school students, BBL teaching method, too, remained more effective than conventional teaching method for the high achievers (t (18) = 3.485, p = .003), for the average achievers (t (18) = 6.913, p < .005) and for the low achievers (t (18) = 4.373, p < .005). It is, therefore, concluded that BBL teaching method is significantly more effective than conventional teaching method to teach mathematics at secondary level. The performance of the students can be enhanced if a teacher manages to activate the innate faculties of human brain of the learners in accordance with its natural physiology.