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Home > Synthesis and Development of Metal Doped Quantum Dots for Environmental Remediation

Synthesis and Development of Metal Doped Quantum Dots for Environmental Remediation

Thesis Info

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Author

Maryam Abbasi

Program

PhD

Institute

Fatima Jinnah Women University

City

Rawalpindi

Province

Punjab

Country

Pakistan

Thesis Completing Year

2018

Thesis Completion Status

Completed

Subject

Environmental Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/bitstream/123456789/10708/1/Maryam%20Abbasi_Env%20Sci_2018_FJWU_PRR.pdf

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676725064978

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The main focus of the present research is the development of efficient catalysts for the degradation of wide range of pollutants present in different environmental compartments. For this purpose, two sets of compounds are synthesized. One class is designated as quantum dots and the second is sulphide based nanoparticles on the basis of particle size. The potential of these materials as candidates for environmental remediation is evaluated through degradation studies of dyes, polyaromatic hydrocarbons and pesticides. Quantum dots were synthesized to act as core (indium phosphide), shell (zinc sulphide) and (silver & copper) doped following the thermal decomposition process. Another series of compounds based on zinc and silver sulphide was attempted. The structure property relationship was assessed through a wide range of techniques including UV-Visible spectroscopy (UV-Vis), Photoluminescence spectrofluorometry (PL), X-ray Diffraction (XRD), Energy dispersive X-ray spectroscopy (EDX), Transmission electron microscopy (TEM) and Thermogravimetry (TGA). The particle size results obtained from TEM supported two ranges; 2.28-4.60 nm and 612 nm for quantum dots and sulphide based nanoparticles, respectively. Each material was spherical in shape with clear lattice fringes. The purity of the product was witnessed by the presence of main elements and doping was in proportion to concentration induced. XRD results of ZnS depicted lattice planes (111), (200), (220), (311), (400), and (331) in good agreement with cubic geometry. It was also found that doping stamped good thermal stability to the synthesized material. Each of the synthesized material was tested as potential photocatalyst candidate for the degradation of representative dyes (crystal violet, Congo red), polyaromatic hydrocarbons (phenanthrene, naphthalene and pyrene) and pesticide (deltamethrin). For this purpose, series of bench scale batch experiments were designed and photocatalytic activity under UV light irradiation was followed on UV-Visible, Gas chromatography coupled with Mass spectrometry, and High performance liquid chromatography.The degradation potential of QDs due to smaller particle size was higher than nanoparticles with optimum efficiency of 95% and 81%, respectively, for both cationic and anionic dyes. The results indicated that degradation of PAHs increased with increase in irradiation time as evident from the reduced intensity of molecular ion peaks at standard retention times.The fragment at m/z 149 represented formation of phthalic acid that is less hazardous than parent compound. The study concludes that each synthesized material can be employed as potential photocatalyst for the degradation of representative pollutants. It is recommended that environmental compartment with mix pollutants can conveniently be treated with a single material to an appreciable extent. The study offers economical and environment friendly remediation model.
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اختر لایمان کی نظم ’’مسجد ‘‘کا تنقیدی جائزہ

منظر نگاری:
اختر الایمان نے جو منظر کشی کی ہے وہ المناک ہوتے ہوئے بھی دل فریب ہے۔اس نظم میں شاعر نے کہیں دور اشارہ کر کے ایک مسجد کی نشاندہی کی ہے۔ برگدی گھنی چھاؤں میں ماضی اور حال گناہگار نمازی کی طرح رات کی تاریک کفن کے نیچے اپنے اعمال پر آہ و زاری کرتے ہیں۔ اسی برگد کی چھاؤں میں ایک ویران سی مسجد ہے جس کا ٹوٹا ہوا کلس پاس بہتی ہوئی ندی کو تکا کرتا ہے۔ اسی مسجد کی ٹوٹی ہوئی دیوار پر کوئی الّو (چنڈول) کوئی پھیکا سا گیت چھیڑ دیا کرتا ہے۔
دور برگد کی گھنی چھاؤں میں خاموش و ملول
جس جگہ رات کے تاریک کفن کے نیچے
ماضی و حال گنہ گار نمازی کی طرح
اپنے اعمال پہ رو لیتے ہیں چپکے چپکے
تشبیہات کا استعمال:
اس نظم میں برگدی گھنی چھاؤں ماضی سے مشابہ ہے۔ رات کو تاریک کفن سے موسوم کیا گیا ہے۔ ماضی و حال کا خاموش و ملول ہونا، شکستہ کلس کا ندی کو تکنا ، بے بسی، مایوسی اورپاسیت کو واضح کرتا ہے۔ چنڈول ایک منحوس پرندہ مانا جاتا ہے اور پھر اس الّو کا کوئی پھیکا سا گیت چھیڑنا یہ بھی توجہ طلب ہے۔ شاعر نے نظم میں ڈوبتے سورج کے لئے ’ سورج کے وداعی انفاس‘کا استعمال کیاہے جس سے اس بات کا اندازہ ہوتا ہے کہ قدرت نے بھی اس مسجد کی طرف منہ موڑ لیا ہے۔
ایک ویران سی مسجد کا شکستہ سا کلس
پاس بہتی ہوئی ندی کو تکا کرتا ہے
اور ٹوٹی ہوئی دیوار پہ چنڈول کبھی
گیت پھیکا سا کوئی چھیڑ دیا کرتا ہے
تجسیم نگاری:
نظم میں جوسب سے بڑی فن کاری دکھائی گئی ہے وہ یہ ہے کہ اس دعاؤں کوسننے والا کوئی شخص نہیں بلکہ ان دعاؤں کے گواہ شام و سحر ہیں...

Pengaruh Konsep Diri dan Disiplin Belajar terhadap Motivasi Belajar Peserta Didik di Sekolah Menengah Pertama Negeri 4 Palu Pada Mata Pelajaran Pendidikan Agama Islam

The purpose of this study is to find out the significant effect of self-concept on learning motivation of VII grade students in SMP Negeri 4 Palu on Islamic Religious Education subjects, (2) knowing the effect of learning discipline on learning motivation of VII grade students at SMP Negeri 4 Palu in the eyes of Islamic Religious Education subjects and (3) determine the effect of self-concept and learning discipline on learning motivation of grade VII students in SMP Negeri 4 Palu on Islamic Religious Education subjects. This study uses a quantitative approach. The population in this study were 220 class VII students of SMP Negeri 4 Palu. The sample was determined using proportional random sampling technique using a formula developed by Isaac and Michael, so that a sample of 135 students was obtained. Primary data were obtained using a questionnaire. Data analysis techniques include descriptive analysis, and regression tests using simple regression and multiple regression. The results showed that (1) There was a significant influence between self-concept on learning motivation of VII grade students in SMP Negeri 4 Palu on Islamic Religious Education subjects, with a significance level of 5%, the magnitude of the effect of self-concept variables on students' learning motivation was 0, 615 means having a high influence (2) There is a significant influence between learning discipline on learning motivation of VII grade students in SMP Negeri 4 Palu on Islamic Religious Education subjects, with a significance level of 5%, the magnitude of the effect of the discipline of learning variables on motivation student learning is 0, 565, (3) There is a significant influence between self-concept and learning discipline on learning motivation of grade VII students in SMP Negeri 4 Palu on Islamic Religious Education subjects, with a significance level of 5%, the high influence of concept variables self and discipline of learning towards learning motivation of VII grade students of SMP Nege ri 4 Palu in Islamic Religious Education subjects is 0, 615. The contribution of self-concept variables and learning discipline to learning motivation variables is R2 x 100% or 0, 6152 x 100% = 37.9%, the remaining 62.1% is determined by other variables outside of this study include the level of interest, talent, attention, parenting parents and others.

Symmetry Analysis and Conservation Laws of Physical Models on Curved Surfaces

Physical models with non-flat background are important in biological mathematics. Most of the biological membranes are not flat in general. For example, membranes which convert energy in mitochondria and chloroplasts are tubes, buds and may be sheets. In most of the biological processes, the geometry of membranes is very important. The organization and shape of the membranes play a vital role in biological processes such as shape change, fusion- division, ion adsorption etc. A cell membrane is a system for exchange of energy and matter from the neighbourhood. Absorption and transformation of conserved quantities such as energy and matter from the environment are one of the characteristics of membranes. The shape of proteins, non zero curvature of membranes and involvement of conserved quantities lead one to discuss physical models on curved surfaces. Conservation laws play a vital role in science and also helpful to construct potential systems which can be used to calculate exact solutions of differential equations. Physical models on curved surfaces govern partial differential equation which need not to be derivable from variational principle. The partial Noether approach is the systematic way to construct the conservation laws for non-variational problems. The group classification and conservation laws for some partial differential equation on curved surfaces are presented in this dissertation. In particular some linear and nonlinear models of heat and wave equation on plane, cone, sphere are classified. The conservation laws for the (1 + 2)-dimensional heat equation on different surfaces are constructed via partial Noether approach and then the results are generalized for the (1+n)-dimensional case. The symmetry conservation laws relation is used to simplify the derived conserved vectors and exact solu- tions are constructed. We also extend these results to a special type of (1 + n)-dimensional linear evolution equation. Potential systems of some models from different sciences are also given. The similar analysis is performed for the (1 + 2)-dimensional wave equation on the sphere, cone and on flat surface. Furthermore, the nonlinear heat equation on curved surfaces is considered. A class of func- tions is found on the plane, sphere and torus, which is not only independent of the number of independent variables but also independent of the background metric. We consider whether the background metric or the nonlinearity have the dominant role in the infinitesimal gen- erators of heat equation on curved manifolds. Then a complete Lie analysis of the time dependent Ginzburg-Landau equation (TDGL model) is presented on the sphere and torus. In addition, for the (1 + n)-dimensional nonlinear wave equation (Klein Gordon Equation) it is proved that there is a class of functions which is independent from number of independent variables. Then for the (1 + 2)-dimensional wave equation it is proved that there is a class of functions which is invariant either the underlying space is a plane, sphere or torus.