Search or add a thesis

Advanced Search (Beta)
Home > Analysis of Unsteady Natural Convective Radiating Gas Flow

Analysis of Unsteady Natural Convective Radiating Gas Flow

Thesis Info

Access Option

External Link

Author

Bakhtiar Ahmad

Program

PhD

Institute

Islamia Collage Peshawar

City

Peshawar

Province

KPK

Country

Pakistan

Thesis Completing Year

2019

Thesis Completion Status

Completed

Subject

Mathemaics

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/12014/1/Bakhtiar%20ahmad%202019%20maths%20icp%20peshwar%20prr.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725492601

Asian Research Index Whatsapp Chanel
Asian Research Index Whatsapp Chanel

Join our Whatsapp Channel to get regular updates.

Similar


Due to diversity in nature, fluids are present everywhere in universe. We go through air, a form of fluid. We use water in our everyday life, which is much important fluid for the perpetuity of living organism. We use fluid in the form of gases for breathing and for different activities of everyday life. The whole universe is covered with the invisible layers of gas. A gas flows through conduction, convections and radiations. The flow of such gaseous materials attracted different researchers of mathematical society. The main theme of this Thesis is the investigation of the behavior of thermal diffusion in the radiating flow of gases. Flow is studied in an open ended channel, which is stationary and having uniform temperature. Fluid is gradually moving under the effect of temperature. We used Laplace transform for the solutions of non dimensional fractional governing equations of radiating flow. Moreover Caputo time fractional derivative have been used for the dealing of temporal derivative. Closed form analytical solutions for Velocity field and thermal expansions are expressed as Robotnov function, Wright and Hartley function. The effects of factional order parameter α, Prandtl number Pr, Grashof number Gr, Radiative parameter R are examined by the graphical interpretations. It is observed that small value of time t has a role activator at the fluid velocity for increasing values of factional order parameter α. Where, large value of time ’t’ inhibits the flow of fluid for increasing values of factional order parameter α. Large values decreases velocity but the effect of large value of time with increasing value of Prandtal is not significant. Increased in value of radiating parameter R decrease the speed of gas and finally Grashof number Gr has direct relation with velocity. The fractional differential equation for temperature distribution operated by Laplace transform. The partial differential equation of velocity is solved numerically with nanoparticle namely copper with the water as based fluid by using Stehfests algorithm. The effects of fractional order derivative and physical parameters are graphically investigated.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

حد کا لغوی معنی

حد ایک کثیر المعنی لفظ ہے ۔ ماہرین لغت ، محدثین اور فقہائے کرام نے اس کے کئی معنی بیان کیے ہیں ، جیسا کہ مشہور لغت دان ابن فارس(م:395ھ) حد کی تعریف بیان کرتے ہوئے لکھتے ہیں
"الحد: الحاء والدال أصلان: الأوّل المنع، والثاني طَرَف الشيء.فالحدّ: الحاجز بَيْنَ الشَّيئين. وفلان محدودٌ، إذا كان ممنوعاً. و"إنّه لَمُحارَفٌ محدود"،كأنه قد مُنِع الرِّزْقَ.ويقال للبوَّاب حَدّاد،لمنْعِه النَّاسَ من الدخول۔"1
"مادہ " حا اور دال " اس کی دو اصل ہیں پہلے کا معنی ہے روکنا اور دوسرے کا معنی ہے کسی شے کا کنارہ ، پس حد کا معنی ہے دو چیزوں کے درمیان آڑ ۔ جیسے کہا جاتا ہے کہ "وفلان محدودٌ "جب کہ اس شخص کو روک دیا گیا ۔ " إنّه لَمُحارَفٌ محدود "جیسا کہ وہ رزق سے روک دیا گیا ہے اور دروازے پر کھڑے ہونے والے کو حداد کہا جاتا ہے اس لیے کہ وہ لوگوں کو اندر آنے سے روکتا ہے۔ "
حد آڑ کے معنی میں بھی استعمال ہوتا ہے، جیسا کہ ابن منظور افریقی (م:711ھ)نے بیان کیا ہے
"الحَدُّ الفصل بين الشيئين لئلا يختلط أَحدهما بالآخر أَو لئلا يتعدى أَحدهما على الآخر وجمعه حُدود وفصل ما بين كل شيئين حَدٌّ بينهما۔"2
"حد دو چیزوں کی درمیانی آڑ کو کہتے ہیں تاکہ دونوں آپس میں خلط ملط نہ ہو جائیں۔ یا ان دونوں میں سے ایک دوسری پر زیادتی نہ کرے اور حد کی جمع حدود ہے۔ دو چیزوں کی درمیانی آڑ ان کے لیے حد ہوتی ہے۔ "
لفظ حد بطور روکنا بھی لیا جاتا ہے، راغب ا صفہانی(م:502ھ) اس حوالے سے بیان کرتے ہیں
"الحد الحاجز بین الشیئین الذی یمنع اختلاط احدھمابالاخر۔"3
" حدسے مراد وہ شے ہے جو دو اشیا کو باہم ملنے سے روک دے۔ "
دو چیزوں کی درمیان آڑ کو حد کہتے ہیں ، جیسا...

Difference in the Characteristics of Imposter Syndrome in Dental Students of Preclinical and Clinical Phase

Background: People suffering from imposter syndrome despite being competent consider themselves less skillful and incapable. Such individuals are also more prone to regret their choice of career with consequent early drop out, experience burnout, more prone to medical errors, absenteeism and low job satisfaction.  The current study aims to determine the difference in the characteristics of imposter syndrome in dental students of preclinical and clinical phase and its gender predisposition. Objectives: 1. To find out the frequency and characteristics of imposter syndrome among dental students. 2. To evaluate the differences in the characteristics of imposter syndrome among dental students of preclinical and clinical year. 3. To determine gender predisposition of imposter syndrome among dental students. Methods: The cross-sectional study was conducted on 138 dental students of CMH Lahore Medical and Dental College. A validated questionnaire (Clance IP Scale) containing 20 items with 5-point Likert scale was used to collect data by convenient sampling technique. The characteristics of IP were determined by adding the scores of all items. Descriptive statistics were done, chi-square applied, p-value <0.05 was considered significant. Results: One hundred and thirty-eight students filled the IP Scale. The frequency of imposter syndrome is found to be 52.1% among Dental Students. Majority (72) of the dental students have frequent to intense imposter feelings. There is non-significant difference in the IP characteristics of male and female students. No significant difference in the characteristics of imposter syndrome is found between dental students of preclinical and clinical year. Conclusions: There frequency of imposter syndrome is high among Dental students. Non-significant difference in the IP characteristics is found between male and female students as well as students of preclinical and clinical year.

New Insight into the Levels, Distribution and Risk Diagnosis of Flame Retardants Frs in Potable Water, Air and Dust from Different Altitudinal Zones of Pakistan

Currently limited information/knowledge is available about the occurrence, sources and distribution of flame retardants (FRs) in the potable water, air and dust as well as their associated health risk to the exposed human population. This is the first study designed to probe selected flame retardants (FRs) in the indoor and outdoor air and dust as well as potable water samples at different altitudinal zones (industrial, rural and background) of Pakistan with special emphasis upon their occurrence, distribution and associated health risk diagnosis. Therefore, the selected FRs viz., Polybrominated diphenylethers (PBDEs), Dechlorane plus (DP), Novel brominated flame retardants (NBFRs) and Organophosphate flame retardants (OPFRs)) in a total of 38 air (indoor and outdoor), 82 dust (indoor and outdoor) and 39 potable water samples were collected from different altitudinal zones. The targeted FRs were analyzed by Gas chromatograph Agilent 7890A coupled to mass spectrometer (5973C MSD) in electron capture negative ionization (ECNI) and GC/MS-MS Agilent 7000A triple Quad operating in Selective ion mode (SIM). Results for the targeted FRs in the air (indoor and outdoor) samples collected from different altitudinal zones showed the trends as: ΣNBFRs > ΣPBDEs > ΣDP, While for the dust (indoor and outdoor) samples were ranked: ΣOPFRs > ΣNBFRs > ΣPBDEs > ΣDP. Significant correlation among FRs in the indoor and outdoor air at different altitudinal zones suggested similar source origin of FRs used in different consumer goods. Significant correlation in the FRs levels between the indoor and outdoor dust suggested the potential intermixing of these compounds between different environmental matrices. Similarly, Principal component analysis (PCA)/Multiple linear regression (MLR) predicted the percent contribution of FRs from different consumer products in the indoor and outdoor dust of industrial, rural and background zones to trace their source origin. Furthermore, air mass trajectories for air samples revealed that movement of air over industrial area sources influenced concentrations of FRs at rural sites. While, for dust samples, the forward and backward air mass trajectories showed that the FRs detected in the background zones reveal the dust-bound FRs suspended in the air might be shifted from different warmer zones or consumers products available/used in the same zones. Elevated concentrations of FRs in the potable water samples were revealed in the industrial zones followed by rural and background zones, while the decreasing trends for FRs in the potable water samples highlighted were: ΣOPFRs > ΣPBDEs > ΣNBFRs > ΣDP due to the much higher water solubility for OPFRs as compared to the other BFRs. Among the analyzed FRs, Tris-(2-chloroisopropyl)-phosphate (ΣTCPP), anti-DP, BDE-47 and 1,2- bis(pentabromodiphenyl)ethane (DBDPE) were the dominant compounds in three selected zones. Principal component analysis (PCA) revealed that most of the FRs are associated with the industrial zones. It is suggested that FRs might be leached out from wastewater bodies and subsequently mixed with nearby potable water facilities. FRs may also spill out from the aluminum or plastic pipes and tanks most commonly used for potable water storage in Pakistan. xv The FRs concentrations, estimated daily intake (EDI) and the hazard quotient (HQ) in potable water, air and dust samples were recorded higher in toddlers as compared to adults. Moreover, the indoor air and dust samples showed higher FRs levels, EDI and HQ than outdoor air and dust samples. It was found that in air, dust and potable water samples an elevated FRs concentrations, EDI and HQ were recorded in the industrial zones followed by rural and background zones. HQs for FRs in the Children/toddlers and adults via potable water consumption and indoor and outdoor dust were <1 highlighting no risk to the vulnerable population. While on the other hand, the HQ values >1 in toddlers and adults population warrants a health risk for BDE-47 and -99 in most of the indoor and outdoor air samples at the industrial zones; while for BDE-47 in the toddlers at indoor and outdoor air samples in some sites at the rural zones of Gujrat and Gujranwala, Pakistan. The results of this study will provide a baseline record for FRs (PBDEs, DP, NBFRs and OPFRs) concentrations in the indoor and outdoor air, dust and potable water at different altitudinal zones in Pakistan. Strict implementations in regard of FRs associated products are needed to minimize the future health concerns through FRs exposure. Alternative products should be introduced to reduce the hazards from FRs. Furthermore, detailed studies are required to assess the long range transport of FRs and modeling approaches for better understanding of their distribution in different environmental compartments. Key words: Flame retardants, Air, Dust, Potable water, Exposure pathways, Pakistan