Search or add a thesis

Advanced Search (Beta)
Home > Photodetachment of Linear Systems

Photodetachment of Linear Systems

Thesis Info

Access Option

External Link

Author

Rehman, Amin Ur

Program

PhD

Institute

Hazara University

City

Mansehra

Province

KPK

Country

Pakistan

Thesis Completing Year

2012

Thesis Completion Status

Completed

Subject

Physics

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/1825

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726889871

Similar


This dissertation is focused on the photodetachment of linear homo- nuclear negative molecular ions in and in the absence of external field. A new approach of N-center model (NCM) and theoretical imaging method are employed to study these systems. The detached-electron wave function from a linear tetra-atomic negative ion is first formulated as a superposition of the electron waves originating from the four cores of the ion. The ion behaves as a coherent source of the detached electron waves shined with polarized laser light. The detached electron flux is then evaluated on an observation plane placed at a very large distance from the system. The strong oscillations in the detached-electron flux reveals quantum interference effects. The total photodetachment cross section is evaluated by integrating this electron flux for all angles. It is observed that the amplitude of oscillations varies as we change the laser orientation with molecular axis. It is maximum when polarized laser light is parallel to the molecular axis and then it gradually decreases with the increase in the angle. Eventually it becomes zero as the polarization of the laser light is perpendicular to the molecular axis. The cross section is also found to be dependent on the interatomic distance. If the interatomic distance is very large then the amplitude of oscillations is negligibly small. This is due to the fact that at very large interatomic distance, the linear tetra-atomic molecule is broken into three neutral atoms and an atomic negative ion and under this condition the total cross section shows smooth behavior. Theoretical imaging method is used to investigate the surface induced effects in the photodetachment cross section of H 2 − . The photodetachment of H 2 − in the vicinity of a soft reflecting wall is investigated and analytical expressions for the differential and total cross sections are derived. It has been iiobserved that the wall induces oscillatory structure in the photodetachment cross section of H 2 − and the total cross section is similar to the cross section of a tetra-atomic negative ion. The asymptotic cross section of our result is identical to the already published results of the closed orbit theory. We hope that our theoretical studies may be helpful to understand the structure and dynamics of linear tetra-atomic systems like C 2 H 2 − , Ar 2 HF − , GeC 2 N − , C 2 HS − as well as H 2 − near an interface in the photodetachment microscopy experiments.
Loading...
Loading...

Similar Books

Loading...

Similar Chapters

Loading...

Similar News

Loading...

Similar Articles

Loading...

Similar Article Headings

Loading...

میجر علی حماد عباسی

پرنس انجم قدر ؍ میجر علی حماد عباسی
آل انڈیا شیعہ کانفرنس کے صدر پرنس انجم قدر کی وفات ملک و ملت کا بڑا حادثہ ہے، سنیوں سے بھی ان کے روابط تھے، وہ دونوں فرقوں میں اتحاد و مفاہمت کے بڑے حامی تھے اور مشترکہ ملی مسائل کے حل کے لیے سنیوں کے ساتھ ہر جدوجہد میں شریک رہتے تھے۔ مسلم پرنسپل لابورڈ، مسلم مجلس مشاورت اور بابری مسجد تحریک سے ان کا گہرا تعلق تھا، دوسرا حادثہ میجر علی حماد عباسی کی اچانک وفات ہے۔ وہ شبلی کالج میں انگریزی کے استاد اور آخر میں پرنسپل ہوئے، پڑھنے لکھنے کا اچھا ذوق تھا اور مشرقی و مغربی ادب پر خاصی نظر تھی۔ وقتاً فوقتاً طنزیہ و مزاحیہ اور ادبی و تنقیدی مضامین لکھتے تھے جن کے بعض مجموعے چھپ گئے ہیں، طالب علمی کے زمانے ہی سے دارالمصنفین برابر آتے تھے جس کا سلسلہ آخر تک قائم رہا۔ پروفیسر مجیب الحسن کی کتاب کشمیر انڈر سلطانز کا اردو ترجمہ ’’کشمیر سلاطین کے عہد میں‘‘ کے نام سے کیا جو دارالمصنفین سے شائع ہوا۔
(ضیاء الدین اصلاحی، ستمبر ۱۹۹۷ء)

 

سیدہ زینب ؓ کا رسول اللہﷺ سے نکاح اور مستشرقین

Many western scholars have tried to interpret the Holy Qur’an into other languages of the world. William Montgomery Watt and Robert Spencer are included in the list of those commentators of the Qur’an who have presented their Quranic commentary in English language. But while interpreting the verses of the Holy Qur’an about the life, character and teachings of the Holy Prophet both the scholars have fabricated the teachings of the Holy Qur’an. Therefore, the main purpose of this study is to compare and analyze the interpretation of both western writers about the verses of Sūrah al-Aḥzāb in which the necessary information about the marriage of Prophet Muhammad with Hazrat Zainab has been discussed. Through the text analysis method and comparative and analytical approach, this article has raised some of the errors and propaganda elements found in the commentaries of both the Western scholars. The article proves that the writings of Western scholars like this need to be refined and scrutinized carefully in maintaining the sanctity of Islam and respecting the rights of the Prophet Muhammad (PBUH). This paper concludes that all such allegations are either based on fabricated historical reports or false interpretations and misunderstanding of the facts.

Evaluation of Conflict Management Skills: Developing a Model for Secondary School Principals

Conflict among staff is a natural phenomena or a part of daily school life. If these are not handled in a positive way, they can affect the staff interpersonal relations which will negatively affect the whole school climate. Different approaches have been in practice for handling conflicts in the schools, e.g. Mediation, Negotiation, Avoidance, Collaboration etc. Acquiring the basic working knowledge of these skills may provide the school teachers and principal with the necessary tools to solve their interpersonal problems/conflicts in a more responsible and productive way. The main focus of this study was to review the existence of conflicts in schools, its nature, types and different conflict resolution strategies which have been adopted by the schools’ principals. A descriptive research design was utilized for collection of data, population of the study consisted of 357 secondary schools of selected districts of KPK in which 250 schools’ teachers and principals were selected. For data analysis Kendall’s Tau B and Kendall’s Tau C were utilized in which teachers and principals’ responses were compared. Findings of the study show that conflicts exist in all the schools which testify the fact that adequate measures need to be taken for its management. Furthermore findings of the study reflect that compromising, collaboration and accommodation styles were preferred by most of the principals. Recommendations are made on the basis of research findings that educators and all the principals should be properly trained in conflict management strategies.