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Research paper thumbnail of Perspective of Nanomaterials in the Performance of Solar Cells

Solar Cells, 2020

Solar cells have a great promise to solve the world energy crises in a sustainable way. In recent... more Solar cells have a great promise to solve the world energy crises in a sustainable way. In recent years, numerous efforts have been devoted on different aspects and performance of solar cells with a common task of achieving higher efficiency to compete with the traditional energy resources. Cost-effectiveness and enhancing power conversion efficiency are the major tasks in the photovoltaic technology. New field of nanotechnology has developed promising possibilities to improve the quality, stability, and performance of solar cells. Nanomaterials can contribute to solar cell design in different ways, which play an important role in their performances. Developments of nanomaterials-based solar cells could reduce the cost and stability for bulk power generation as well as enhance the power conversion efficiency. This book chapter reviews the performances of traditional solar cells and focuses on different contribution of advanced nanomaterials in solar cell advancement.

Research paper thumbnail of Structural and Dielectric Properties of Manganese Ferrite Nanoparticles

Journal of Basic & Applied Sciences, 2012

In this work, Manganese ferrite nanoparticles of various compositions were reproducibly synthesiz... more In this work, Manganese ferrite nanoparticles of various compositions were reproducibly synthesized via coprecipitation route. Variation in structural and dielectric properties was studied by varying the sintering temperature, sintering time and manganese to iron ratio. Structural, compositional and phase properties were investigated by X-ray diffraction (XRD) technique which confirmed the pure normal spinel structure with no other phase/impurity. Particle size, Lattice constant, measured bulk density, X-ray density, Specific Surface Area and Porosity were determined by the standard formulae. Responses of Capacitance and Dielectric constant were studied at room temperature in the frequency range of 600Hz to 1MHz by LCR meter which both showed the exponential decay at low frequency while both became nearly independent of frequency in higher frequency ranges.

Research paper thumbnail of Evaluation of the Traffic Noise Pollution at Some Busiest Sites of Faisalabad City, Pakistan

Academic Research International

Research paper thumbnail of Plasma confinement to enhance the momentum coupling coefficient in ablative laser micro-propulsion: a novel approach

Laser Physics Letters, 2015

Research paper thumbnail of A new perspective of ablative pulsed laser propulsion: study on different morphologies of nano-structured ZnO

Laser Physics Letters, 2015

We report for the first time a new application of four different morphologies including nano-nood... more We report for the first time a new application of four different morphologies including nano-noodles of zinc oxide as a laser ablation micro-thruster. Nano-noodles represent a unique class of materials in which the electrons are confined near the surface owing to the majority of the near surface atoms. The synthesized samples of ZnO were of single phase, having a wurtzite hexagonal structure. Three different morphologies, viz. initial (nanoparticles), intermediate (nano-noodles) and final (complete nano-noodles) of zinc oxide were ablated using a Nd : YAG laser operating at 1064 nm for the measurement of propulsion parameters. The momentum coupling coefficient (Cm) and the specific impulse (Isp) were evaluated using the non-contact optical triangulation method. It has been observed that the morphology of the material affects the laser ablation propulsion (LAP) parameters. For each sample, the laser fluence for the optimum coupling coefficient owing to the plasma shielding effect has also been found. The synthesized nanostructured zinc oxide samples have been found useful as efficient laser propellants that can be used in a variety of applications due to diversity in their momentum coupling coefficient and specific impulse values.

Research paper thumbnail of Refinement in the structural and magnetic properties of Co0.5Ni0.5Fe2O4 and its application as laser micro-propellant using ablation confinement

Journal of Magnetism and Magnetic Materials, 2015

Research paper thumbnail of Enhancement in the germination, growth and yield of okra (Abelmoschus esculentus) using pre-sowing magnetic treatment of seeds

Indian journal of biochemistry & biophysics, 2012

The effect of pre-sowing magnetic treatments was investigated on germination, growth and yield of... more The effect of pre-sowing magnetic treatments was investigated on germination, growth and yield of okra (Abelmoschus esculentus cv. Sapz pari). The dry okra seeds were exposed to sinusoidal magnetic field induced by an electromagnet. The average magnetic field exposure was 99 mT for 3 and 11 min and seeds with no magnetic field treatment were considered as control. Both treated and non-treated seeds were sown in experimental plots (120 m2) under similar conditions. Samples were collected at regular intervals for statistical analysis. A significant increase (P < 0.05) was observed in germination percentage, number of flowers per plant, leaf area (cm2), plant height (cm) at maturity, number of fruits per plant, pod mass per plant and number of seeds per plant. The 99 mT for 11 min exposure showed better results as compared to control.

Research paper thumbnail of He-Ne Laser-Induced Improvement in Biochemical, Physiological, Growth and Yield Characteristics in Sunflower (Helianthus annuus L.)

Photochemistry and Photobiology, 2011

Research paper thumbnail of Effects of Different Doses of Low Power Continuous Wave He-Ne Laser Radiation on Some Seed Thermodynamic and Germination Parameters, and Potential Enzymes Involved in Seed Germination of Sunflower (Helianthus annuus L.)

Photochemistry and Photobiology, 2010

In this study, water-soaked seeds of sunflower were exposed to He-Ne laser irradiation of differe... more In this study, water-soaked seeds of sunflower were exposed to He-Ne laser irradiation of different energies to determine whether or not He-Ne laser irradiation caused changes to seed thermodynamic and germination parameters as well as effects on the activities of germination enzymes. The experiment comprised four energy levels: 0 (control), 100, 300 and 500 mJ of laser energy and each treatment replicated four times arranged in a completely randomized design. The experimentation was performed under the greenhouse conditions in the net-house of the

Research paper thumbnail of A novel laser assisted structure refinement of Co 0.5 Zn 0.5 Fe 2 O 4

Laser Physics Letters, 2014

A major issue in the synthesis of ferrites using the co-precipitation technique is the refinement... more A major issue in the synthesis of ferrites using the co-precipitation technique is the refinement in the crystal structure. We report in this work for the first time the use of a pulsed Nd:YAG (1064 nm) laser to refine the structure of spinel ferrite using pre-digestion irradiation of the sample. In view of the technological importance of single phase Co–Zn ferrite particles, an attempt has been made to remove the unwanted peaks through laser irradiation. It is well known that the wet chemical co-precipitation technique yields homogeneous ferrite nanoparticles but that it requires subsequent thermal treatment of long duration. It has been observed that the thermal energy imparted to the finite solution due to IR laser enhances the crystallinity of ferrites and refines the spinel structure. The additional phases that were present in the as-synthesized Co–Zn ferrite have been removed using the 1064 nm pulsed Nd:YAG laser. The XRD analysis and TEM micrographs showed that the pre-digestion laser irradiation of ferrite solution not only removed the unwanted peaks but also affected the average crystallite size. The average diameter of ferrite particles reduced to 20 nm due to laser irradiation.

Research paper thumbnail of He–Ne laser-induced changes in germination, thermodynamic parameters, internal energy, enzyme activities and physiological attributes of wheat during germination and early growth

Laser Physics Letters, 2013

ABSTRACT Using low power continuous wave He–Ne laser irradiation of seeds, the germination charac... more ABSTRACT Using low power continuous wave He–Ne laser irradiation of seeds, the germination characteristics, thermodynamic changes and enzyme activities as well as changes in morphological attributes were explored for wheat (Triticum aestivum L. cv. S-24) cultivar. The changes in thermodynamic properties such as change in enthalpy (ΔH), entropy generation [(ΔSe)], entropy flux [(ΔSc)], entropy generation ratio [(ΔS)e/Δt], and entropy flux ratio [(ΔS)c/Δt] showed significant (P &lt; 0.05) changes at an energy level of 500 mJ. The germination energy (GE), germination percentage (G%), germination index (GI) as well as α-amylase and protease activities was also found to be higher at 500 mJ, while the mean emergence time (MET) and time for 50% germination (E50) decreased for 300 mJ irradiance. The internal energy of the seeds increased significantly at all laser energy levels, but was highest for 500 mJ 72 h after sowing. The enzyme activities increased up to 24 h after sowing and then declined. The activities of α-amylase and protease were found to be positively correlated with the plant physiological attributes. These results indicate that low power continuous wave He–Ne laser (632 nm) treatment has considerable biological effects on seed metabolism during germination as well as on later vegetative growth.

Research paper thumbnail of Lead Pollution Measurement Along National Highway and Motorway in Punjab, Pakistan

Journal of Basic & Applied Sciences, 2012

A study was conducted to determine qualitative and quantitative lead contamination in soil and ve... more A study was conducted to determine qualitative and quantitative lead contamination in soil and vegetation along two major roadsides of Pakistan using Atomic Absorption Spectroscopy. There has been a rapid increase in vehicles on the highways using petroleum products, which has caused considerable raised the quantity of lead in the atmosphere increasing the risk to health. Laser Induced Breakdown Spectroscopy (LIBS) was used as multi elemental analysis technique to cross confirm the lead contamination in the samples. The samples of soil and grass were collected from each location 100m away from the edge of roads at every 25m. The levels of lead were found to be 125mg/kg to 87mg/kg respectively in soil and grass. Hence there is high accumulation of lead in roadside soil and vegetation of linking roads of highly populated cities of Pakistan, Faisalabad and Lahore.

Research paper thumbnail of Perspective of Nanomaterials in the Performance of Solar Cells

Solar Cells, 2020

Solar cells have a great promise to solve the world energy crises in a sustainable way. In recent... more Solar cells have a great promise to solve the world energy crises in a sustainable way. In recent years, numerous efforts have been devoted on different aspects and performance of solar cells with a common task of achieving higher efficiency to compete with the traditional energy resources. Cost-effectiveness and enhancing power conversion efficiency are the major tasks in the photovoltaic technology. New field of nanotechnology has developed promising possibilities to improve the quality, stability, and performance of solar cells. Nanomaterials can contribute to solar cell design in different ways, which play an important role in their performances. Developments of nanomaterials-based solar cells could reduce the cost and stability for bulk power generation as well as enhance the power conversion efficiency. This book chapter reviews the performances of traditional solar cells and focuses on different contribution of advanced nanomaterials in solar cell advancement.

Research paper thumbnail of Structural and Dielectric Properties of Manganese Ferrite Nanoparticles

Journal of Basic & Applied Sciences, 2012

In this work, Manganese ferrite nanoparticles of various compositions were reproducibly synthesiz... more In this work, Manganese ferrite nanoparticles of various compositions were reproducibly synthesized via coprecipitation route. Variation in structural and dielectric properties was studied by varying the sintering temperature, sintering time and manganese to iron ratio. Structural, compositional and phase properties were investigated by X-ray diffraction (XRD) technique which confirmed the pure normal spinel structure with no other phase/impurity. Particle size, Lattice constant, measured bulk density, X-ray density, Specific Surface Area and Porosity were determined by the standard formulae. Responses of Capacitance and Dielectric constant were studied at room temperature in the frequency range of 600Hz to 1MHz by LCR meter which both showed the exponential decay at low frequency while both became nearly independent of frequency in higher frequency ranges.

Research paper thumbnail of Evaluation of the Traffic Noise Pollution at Some Busiest Sites of Faisalabad City, Pakistan

Academic Research International

Research paper thumbnail of Plasma confinement to enhance the momentum coupling coefficient in ablative laser micro-propulsion: a novel approach

Laser Physics Letters, 2015

Research paper thumbnail of A new perspective of ablative pulsed laser propulsion: study on different morphologies of nano-structured ZnO

Laser Physics Letters, 2015

We report for the first time a new application of four different morphologies including nano-nood... more We report for the first time a new application of four different morphologies including nano-noodles of zinc oxide as a laser ablation micro-thruster. Nano-noodles represent a unique class of materials in which the electrons are confined near the surface owing to the majority of the near surface atoms. The synthesized samples of ZnO were of single phase, having a wurtzite hexagonal structure. Three different morphologies, viz. initial (nanoparticles), intermediate (nano-noodles) and final (complete nano-noodles) of zinc oxide were ablated using a Nd : YAG laser operating at 1064 nm for the measurement of propulsion parameters. The momentum coupling coefficient (Cm) and the specific impulse (Isp) were evaluated using the non-contact optical triangulation method. It has been observed that the morphology of the material affects the laser ablation propulsion (LAP) parameters. For each sample, the laser fluence for the optimum coupling coefficient owing to the plasma shielding effect has also been found. The synthesized nanostructured zinc oxide samples have been found useful as efficient laser propellants that can be used in a variety of applications due to diversity in their momentum coupling coefficient and specific impulse values.

Research paper thumbnail of Refinement in the structural and magnetic properties of Co0.5Ni0.5Fe2O4 and its application as laser micro-propellant using ablation confinement

Journal of Magnetism and Magnetic Materials, 2015

Research paper thumbnail of Enhancement in the germination, growth and yield of okra (Abelmoschus esculentus) using pre-sowing magnetic treatment of seeds

Indian journal of biochemistry & biophysics, 2012

The effect of pre-sowing magnetic treatments was investigated on germination, growth and yield of... more The effect of pre-sowing magnetic treatments was investigated on germination, growth and yield of okra (Abelmoschus esculentus cv. Sapz pari). The dry okra seeds were exposed to sinusoidal magnetic field induced by an electromagnet. The average magnetic field exposure was 99 mT for 3 and 11 min and seeds with no magnetic field treatment were considered as control. Both treated and non-treated seeds were sown in experimental plots (120 m2) under similar conditions. Samples were collected at regular intervals for statistical analysis. A significant increase (P < 0.05) was observed in germination percentage, number of flowers per plant, leaf area (cm2), plant height (cm) at maturity, number of fruits per plant, pod mass per plant and number of seeds per plant. The 99 mT for 11 min exposure showed better results as compared to control.

Research paper thumbnail of He-Ne Laser-Induced Improvement in Biochemical, Physiological, Growth and Yield Characteristics in Sunflower (Helianthus annuus L.)

Photochemistry and Photobiology, 2011

Research paper thumbnail of Effects of Different Doses of Low Power Continuous Wave He-Ne Laser Radiation on Some Seed Thermodynamic and Germination Parameters, and Potential Enzymes Involved in Seed Germination of Sunflower (Helianthus annuus L.)

Photochemistry and Photobiology, 2010

In this study, water-soaked seeds of sunflower were exposed to He-Ne laser irradiation of differe... more In this study, water-soaked seeds of sunflower were exposed to He-Ne laser irradiation of different energies to determine whether or not He-Ne laser irradiation caused changes to seed thermodynamic and germination parameters as well as effects on the activities of germination enzymes. The experiment comprised four energy levels: 0 (control), 100, 300 and 500 mJ of laser energy and each treatment replicated four times arranged in a completely randomized design. The experimentation was performed under the greenhouse conditions in the net-house of the

Research paper thumbnail of A novel laser assisted structure refinement of Co 0.5 Zn 0.5 Fe 2 O 4

Laser Physics Letters, 2014

A major issue in the synthesis of ferrites using the co-precipitation technique is the refinement... more A major issue in the synthesis of ferrites using the co-precipitation technique is the refinement in the crystal structure. We report in this work for the first time the use of a pulsed Nd:YAG (1064 nm) laser to refine the structure of spinel ferrite using pre-digestion irradiation of the sample. In view of the technological importance of single phase Co–Zn ferrite particles, an attempt has been made to remove the unwanted peaks through laser irradiation. It is well known that the wet chemical co-precipitation technique yields homogeneous ferrite nanoparticles but that it requires subsequent thermal treatment of long duration. It has been observed that the thermal energy imparted to the finite solution due to IR laser enhances the crystallinity of ferrites and refines the spinel structure. The additional phases that were present in the as-synthesized Co–Zn ferrite have been removed using the 1064 nm pulsed Nd:YAG laser. The XRD analysis and TEM micrographs showed that the pre-digestion laser irradiation of ferrite solution not only removed the unwanted peaks but also affected the average crystallite size. The average diameter of ferrite particles reduced to 20 nm due to laser irradiation.

Research paper thumbnail of He–Ne laser-induced changes in germination, thermodynamic parameters, internal energy, enzyme activities and physiological attributes of wheat during germination and early growth

Laser Physics Letters, 2013

ABSTRACT Using low power continuous wave He–Ne laser irradiation of seeds, the germination charac... more ABSTRACT Using low power continuous wave He–Ne laser irradiation of seeds, the germination characteristics, thermodynamic changes and enzyme activities as well as changes in morphological attributes were explored for wheat (Triticum aestivum L. cv. S-24) cultivar. The changes in thermodynamic properties such as change in enthalpy (ΔH), entropy generation [(ΔSe)], entropy flux [(ΔSc)], entropy generation ratio [(ΔS)e/Δt], and entropy flux ratio [(ΔS)c/Δt] showed significant (P &lt; 0.05) changes at an energy level of 500 mJ. The germination energy (GE), germination percentage (G%), germination index (GI) as well as α-amylase and protease activities was also found to be higher at 500 mJ, while the mean emergence time (MET) and time for 50% germination (E50) decreased for 300 mJ irradiance. The internal energy of the seeds increased significantly at all laser energy levels, but was highest for 500 mJ 72 h after sowing. The enzyme activities increased up to 24 h after sowing and then declined. The activities of α-amylase and protease were found to be positively correlated with the plant physiological attributes. These results indicate that low power continuous wave He–Ne laser (632 nm) treatment has considerable biological effects on seed metabolism during germination as well as on later vegetative growth.

Research paper thumbnail of Lead Pollution Measurement Along National Highway and Motorway in Punjab, Pakistan

Journal of Basic & Applied Sciences, 2012

A study was conducted to determine qualitative and quantitative lead contamination in soil and ve... more A study was conducted to determine qualitative and quantitative lead contamination in soil and vegetation along two major roadsides of Pakistan using Atomic Absorption Spectroscopy. There has been a rapid increase in vehicles on the highways using petroleum products, which has caused considerable raised the quantity of lead in the atmosphere increasing the risk to health. Laser Induced Breakdown Spectroscopy (LIBS) was used as multi elemental analysis technique to cross confirm the lead contamination in the samples. The samples of soil and grass were collected from each location 100m away from the edge of roads at every 25m. The levels of lead were found to be 125mg/kg to 87mg/kg respectively in soil and grass. Hence there is high accumulation of lead in roadside soil and vegetation of linking roads of highly populated cities of Pakistan, Faisalabad and Lahore.