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Linear and Nonlinear Dynamics of Dense Fermi Plasma

Thesis Info

Author

Sughra Bibi

Supervisor

Arshad M Mirza

Department

Department of Physics, QAU

Program

Mphil

Institute

Quaid-i-Azam University

Institute Type

Public

City

Islamabad

Province

Islamabad

Country

Pakistan

Thesis Completing Year

2013

Thesis Completion Status

Completed

Page

69

Subject

Physics

Language

English

Other

Call No: DISS / M.Phil / PHY 961

Added

2021-02-17 19:49:13

Modified

2023-02-19 12:33:56

ARI ID

1676718912493

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ڈاکٹر سید محمود

ڈاکٹرسید محمود
افسوس ہے ڈاکٹر سےّدمحمود بھی رخصت ہوگئے۔وفات کے وقت عمر ۸۲ برس کی تھی۔مرحوم برلن کے پی۔ایچ۔ڈی اورانگلستان سے بارایٹ لاء اور گھر کے بھی بڑے خوشحال تھے۔ لیکن قومی وملّی خدمت کاجذبہ شروع ہی سے تھا اس لیے اولاً تحریکِ خلافت اور پھر تحریکِ آزادی دونوں میں ہراوّل دستہ کے فرد رہے، اس جرم کی پاداش میں کئی مرتبہ جیل گئے اور قید وبند کی سختیاں انگیز کیں پھر قومی حکومت بنی توریاست اورمرکز دونوں میں وزیر رہے۔ کانگرس ورکنگ کمیٹی کے ممبر سالہا سال رہے ۔آل انڈیا کانگرس کمیٹی کے سکریٹری بھی رہ چکے تھے۔اوّل درجہ کے نیشنلسٹ ہونے کے باوجود دل اوردماغ دونوں کھلا رکھتے تھے۔ چنانچہ تقسیم کے بعد مسلسل فسادات ہوئے اور مسلمانوں کے ساتھ ناانصافی ختم نہیں ہوئی توانہوں نے قومی سطح پراس کاانسداد کرنے کی غرض سے مجلس مشاورت بنائی اور چند سال اس کے صدر کی حیثیت سے ملک کادورہ کیا لیکن جب انہوں نے محسوس کیاکہ ان کے چند رفیق اس پلیٹ فارم کو اپنے فرقہ پر ورانہ مقاصد کے لیے استعمال کررہے ہیں تو وہ اس سے الگ ہوگئے لیکن خانہ نشین پھر بھی نہیں ہوئے اورمسلمانوں کی فلاح و بہبود کے کاموں میں حِصّہ لیتے رہے۔مرحوم کا علمی اورادبی ذوق بھی بہت شگفتہ اورشائستہ تھا۔سیاسی مصرفیتوں میں تھوڑا بہت انگریزی اوراردو میں جو کچھ لکھا ہے بہت خوب لکھاہے۔ اخلاقی اعتبارسے نہایت باوضع، بامروت شریف الطبع اورخلیق بزرگ تھے۔ان کی وفات سے ملک میں عموماً اورمسلمانوں میں خصوصاً جوخلا پیدا ہواہے وہ پُرنہیں ہوسکے گا۔اللھم اغفرلہٗ وارحمہ۔ [اکتوبر ۱۹۷۱ء]

Determining the Occupational Health and Safety of Workers in The Food Manufacturing Sector of Pakistan

Background: For organizations, conducting work in a safe environment has become mandatory under the provisions and guidelines provided by international and local laws. Occupational health and safety (OHS) standards have become a requisite in almost every industry these days; however, many organizations in developing countries are negligent at adhering to the safety measures, and there is also an absence of proper monitoring. Objective: Our objective was to determine the occupational health and safety standards that are prevailing in the food manufacturing sector of Pakistan. For this, we approached several food manufacturing companies and conducted interviews with quality assurance managers and health and safety executives to evaluate and analyze the workplace conditions to understand their OHS practices. Methods: We conducted 7 interviews with quality assurance managers in the food manufacturing and services companies of Pakistan. The interview guide was used for eliciting responses and a coding method was used to arrive at the themes of the data gathered. Results: The interviews conducted with quality assurance managers and those working to ensure that safety measures are practiced in their company, showed that the export-oriented food manufacturing companies in Pakistan are following OHS standards, as it has become a necessity, with numerous benefits such as ensuring worker safety, maintaining company reputation. However, the extent to which these measures are implemented and strictly followed varies, as there are certain issues that arise when companies try to follow and implement OHS practices The problems vary from company to company however, most of them relate to worker adaptability, costs, and training needs.  OHS situation in local firms is concerning. Most of them do not have HSE officers, not the concept of toolbox talk, no preventive and safety measures.  These poor practices make the situation unsafe, which lead to fatalities Conclusion: By establishing a national framework for policies and legislations as per the conventions of ILO for a better workplace environment along with proper law enforcement improvement in occupational health and safety domain can be achieved.      

Determination of Selected Phenolic Compounds from Biological and Natural Samples Using Capillary Electrophoresis and Hplc.

Phenolic compounds are widely present in plant kingdom and thus are common components of the human diet, generally found in both edible and inedible plants. These are chemically complex substances consisting of an aromatic ring which contain one or more hydroxyl substituents and their structures may range from a simple phenolic molecule to that of a complex high-molecular mass polymer including phenolic acids, coumarins, tannins and flavonoids. They show a wide range of biological activities such as anti-oxidant, anti-viral, anti-allergic, cardioprotective, anti-carcinogenic, anti-inflammation, anti-estrogen etc. Due to these health benefits and the steady progress of medicinal sciences, analytical techniques for their characterization and quantification are required. Several methods for the determination of phenolic compounds have been described in the literature. But most of these methods have limited resolution, low sensitivity and require long time for analysis. Capillary electrophoresis (CE) offer several advantages over other methods because of its extremely high efficiency, small sample volume, high speed, and good resolution. Reversed-phase high performance liquid chromatography (RP-HPLC) is also the most commonly used analytical technique for the analysis of phenolic compounds as it does not require derivatization prior to analysis. In our present study, five methods have been developed for the determination of phenolic compounds from biological samples (human blood serum) and some natural samples (fruits, vegetables, herbs and spices). First study describes the development of a micellar electrokinetic chromatography (MEKC) method for the determination of naringenin in real samples including citrus fruit juices and human blood serum, using photodiode array (PDA) detector. The effects of several CE parameters including concentration and pH of the running buffer, voltage, injection time and concentration of sodium dodecyl sulfate (SDS) were optimized. Under the optimum conditions, naringenin could be well determined within 6 minutes in a 40mM borate buffer containing 40mM SDS at pH 9.0 and an applied voltage of 25 KV. For the quantitative determination of naringenin (flavonoid aglycone) in juice samples, the naringin (flavonoid glycoside) was hydrolysed and the resulting aglycone was identified and quantified. The calibration curve was linear in the studied concentration range from 0.1 to 50 µg/ml (R2=0.995). The detection limit and limit of quantification was found to be 0.05 and 0.19 µg/ml, respectively. The second method describes the development and validation of a fast capillary zone electrophoretic (CZE) method for determination of quercetin, rutin, naringin and naringenin in various fruits, such as Apples (Malus domestica), Oranges (Citrus sinenis), Grapefruits (Citrus paradisi) and Ber (Ziziphus mauritiana L.) using photodiode array (PDA) detector. Under the optimum conditions, all four flavonoids were well determined in a 10 mM borate buffer of pH 8.5 within 10 min, while applied voltage was 25 kV. Naringin, naringenin and quercetin were found to have linear response in the range of 3.12-200 µg/mL where as rutin’s response was linear from 6.25 µg/mL to 200 µg/mL. LOD of naringin, naringenin, rutin and quercetin was found to be 0.406, 0.314, 0.582 and 0.333 µg/mL, respectively and LOQ of naringin, naringenin, rutin and quercetin was found to be 1.355, 1.046, 1.941 and 1.11, respectively. Long term stability and good reproducibility of developed method is evident from values of relative standard deviations (RSD) which were less than 3% for both migration time and peak height. Third method describes the development and validation of a fast, effective and reliable capillary zone electrophoresis (CZE) method for the determination of five flavonoids (epicatechin, epigallocatechin gallate, chrysin, morin and hesperedin) using 1-butyl-3-methyl imidazolium ionic liquid (IL) as a buffer additive. The effects of several CE parameters including concentration and pH of the running buffer, voltage and concentration of ionic liquid were optimized. Under optimized conditions, all five analytes were well determined within 12 min in a 25 mM borate buffer (pH 9) at an applied voltage of 15 kV and 10 µL of IL was added in the buffer. Validation of the method was performed in terms of linearity, accuracy, VII precision and limit of detection and quantification. The linearity of the calibration curves for 6.25 to 200 µg/mL for EC and chrysin, 12.5 to 200 µg/mL for EGCG and morin, whereas 1.56 to 200 µg/mL for hespiridin. The response was linear with coefficient of determination (R2) = 0.990 for EC, hespiridn and chrysin, 0.992 for morin and 0.988 for EGCG. LOD and LOQ were obtained within 0.4 - 0.5 µg/mL and 1.4 - 1.7 µg/mL, respectively. The proposed method demonstrated good long reproducibility with relative standard deviations (RSD) of less than 3% for both migration time and peak height (n= 5 for intra day and n=3 for inter day ). The developed method was successfully applied on real samples such as green tea, black tea and honey. Fourth study describes the development and validationof capillary electrophoresis method with large volume sample stacking (CE-LVSS) and for the simultaneous determination of seven phenolic compounds namely, naringin, rutin, carnosic acid, apigenin, quercetin, morin and chichoric acid. Optimization was carried out by response surface methodology and set of 20 experiments helped to optimize the parameters such as concentration of buffer, pH of buffer and applied voltage. Analytes were separated on capillary of 50 µm diameter and 56 cm effective length with extended light path using 20 mM borate buffer of pH 9.2. LVSS method was optimized and 3 to 5 fold improvement in detectability was achieved with injection at 100 mbar for 20 s followed by polarity switching at -20 kV for 6 s. Linearity of all seven analytes were observed in the concentration ranges of0.5-50 µg/mL for CZE and 0.1-25 µg/mL for LVSS. LODs were obtained within 0.012 to 0.241 and 0.003 to 0.086 µg/mL, for CZE and LVSS, respectively, whereas LOQs were obtained within 0.041 to 0.802 for CZE and 0.012 to 0.286 µg/mL for LVSS. Recoveries were found to be in the range of 91.1109.8% and 96.3-108.4%for CZE and LVSS, respectively. The developed method has been successfully applied for the quantitative determination of analysed components from different food samples which are important sources of these compounds. Fifth study describes the development and validation of a reverse phase high performance liquid chromatography (RP-HPLC) coupled with DAD detector for the simultaneous determination of five phenolic compounds namely, rutin, VIII naringin, morin, quercetin and p-coumaric acid. Optimization was carried out by using Taguchi experimental design. Set of 32 experiments helped to optimize the parameters such as pH, concentration and percentage of buffer and temperature of the column. Analytes were separated on C8 column within 19 min using isocratic system of 0.1% phosphoric acid and acetonitrile (75: 25 v/v) as mobile phase with flow rate of 0.1 mL/min. Lineartiy of all five analytes were observed in the concentration ranges of 0.5-70 µg/mL. Limit of detection (LOD) and limit of quantification (LOQ) were found to be in the range of 0.024 to 0.081 and 0.081 to 0.269 µg/mL, respectively. Recoveries and relative standard deviations (%RSD) were found to be in the range of 96.7-105.3% and 0.05-1.68%, respectively. The developed method has been successfully applied for the quantitative determination of analysed components from different food samples which are important sources of these compounds.